[MOS-1068] Fix A2DP stream not restarting after song changes

Workaround for the issue that A2DP stream
would sometimes not restart when music
player changes song to the next one.

[MOS-1068] Cleanup BTStack intergration

Code cleanup in various places of
BTStack integration.

[BH-1885] Increase stack size for battery charger task

The battery charger worker had only ~10% free
stack size so it was a possibility to stack overflow.
After increasing the stack by 512 bytes the worker
has ~40% free stack space.

[BH-1657][BH-1833][BH-1854] Add WFI and SDRAM self-refresh mode

* Added mechanism enabling CPU to
enter WFI mode when the OS is
in idle, what results in large
power consumption reduction.
* Added mechanism to switch SDRAM to
self-refresh mode before entering
WFI, what resulted in further power
consumption reduction.

[BH-1857] Fix improper PWM module clock frequency computation

* Fix of the issue that source clock for PWM
module was improperly assumed to be derived
from AHB_CLK, while in reality it is
derived from IPG_CLK, what resulted in
module generating signal with 4 times
lower frequency than the configured
one.
* Cleanups.

[BH-1787] Reboot to MSC endpoint

To allow the automation of gathering logs and swapping out OS images during tests a MSC reboot
endpoint was added. Together with a change to ecoboot, this allows the sending of a "reboot to
MSC" command. The deivce will then reboot and enter MSC mode.

[MOS-1011] Fix frequency switching stability

Multiple fixes of clock switching related
stability issues:
* added RC oscillator hysteresis as in NXP example;
* changed DCDC converter config;
* configure PLL2 to be able to run on any CPU
frequency level;
* added switching to 1.275V (overdrive) voltage
when applying any clock change above 12MHz as
well as LDO or bandgap switching, as done in
Mbed OS' lpm.c for RT1050;
* changed BMCR AXI queues weighs for SDRAM
in JLink scripts to disable operations
reordering, as it is known to cause data
integrity issues;
* extracted some code to separate files;
* smaller or bigger code cleanups.

[MOS-1012] Fix occasional crash when unplugging Pure from PC

Fix of the unhandled error issue that resulted
in occasional device crash when disconnecting
from PC with MC app running.

[MOS-599] Fix undefined phone mode in simulator

Fix of the issue that on simulator phone mode
was in 'undefined' state, what resulted in
no phone mode selected in settings.

[BH-1717] Fix no clock update

The secure RTC can lock and the clock is not updated.
To prevent this situation we reset LP registers (except for
timestamps and alarms) and clear the LVD flag. Then we
enable again LP SRTC.

[MOS-997] Fix failing sync with Mudita Center

Fix of the issue that sync with Mudita Center
would fail often after changes introduced in
CP-1968.

[MOS-238] Use on-chip hardware TRNG as an entropy source

Use hardware TRNG integrated into RT1051 MCU
as an entropy source for builds complied
for RT1051.

[BH-1706] Fix inaccessible MTP on Harmony

Fix of the issue that Harmony's MTP
was constantly locked after MOS-686
fix, as the mechanics of unlocking
was not handled for Harmony at all.

[BH-1702] Fix RTWDOG main DCDC reset

Fix of the issue that RTWDOG performed
only CPU reset in case of timeout due
to IRQ misconfiguration resulting in
RTWDOG handler not being called.

[BH-1673] Fixes for Harmony random resets

Next part of Harmony random resets fixes:
* added RC OSC startup delay as in newest lpm.c;
* changed order of clock source, oscillator and
LDO switching;
* removed connecting internal DCDC load resistor,
as it is only required to speed up converter
startup after it was turned off completely;
* changed DCDC operation mode to continuous
conduction;
* set low VDD_SOC_IN voltage back to 950mV as
suggested in RM.
* added switching DCDC converter mode to
discontinuous conduction for two lowest CPU
clock frequencies, as using CCM mode resulted
in very high current consumption that would
shorten Harmony's life on battery
significantly.

[BH-1700] Add date and time to logs at the startup

Save date and time at the startup of the system for analysis purposes.

[MOS-686] Fixed MTP availability only after phone unlocked

Fixed file access via MTP even when phone is not unlocked.
Now access is granted when the phone is unlocked by the user entering
a passcode. If the phone is not passcode protected (passcode is nor set)
then access to the files is always possible via MTP.

[BH-1583] Fix SNVS LP lockup after debugging

* Fix of the issue that manifested after
running MuditaOS on Harmony via JLink,
which resulted in OS freezing when
trying to set time in normally booted
(via the bootloader) device.
* Minor RTC code cleanup.
* Partial T6 JLink script cleanup.

[BH-1595] USB charger detection issues

* Fixed issues with USB charging port detection
* Fixed memory leak in usb_stack/OS integration layer
* Fixed incorrect handling of software timer
* Minor cleaning/refactor.

[BH-1595] Turned off USB/PC charging

Charging enabled only for a dedicated charger. Users won't be able
to charger while connected to the PC.

[MOS-981] Magnetometer driver cleanup

Cleanup of the magnetometer driver.
Added checks of all I2C operations
return codes and error messages
in case of failures.