[EGD-6518] Change optional methods for the DM

Change numer of minimal optional methods required by the
block device in the disk manager

Signed-off-by: Lucjan Bryndza <lucjan.bryndza@mudita.com>

[EGD-6518] Add EEPROM block device driver for VFS

Add block device driver for the factory EEPROM memory
needed for factory settings (aka personalizations)

Signed-off-by: Lucjan Bryndza <lucjan.bryndza@mudita.com>

[EGD-6576] Corrected after PR comments

I hope this is final

[EGD-6576] Create EEPROM low level driver

Fixed style

[EGD-6576] Create EEPROM low level driver

Working eeprom driver.

[EGD-6576] WiP I2C HAL API need to be modified

WiP

[EGD-6576] Create EEPROM low level driver

Created low level driver for M24256 eeprom & dummy for linux.

[EGD-6678] Fix Display backlight turns on when is set off

Duty cycle update performed only on enabled pwm

[EGD-6651] Fix communication with modem on Linux

Fixed cellular bsp on Linux, so now emulator is able
to comunicate with modem. Fixed memory leak in CellularResult struct.

[EGD-6319] Refactor cellular modem directory

- Removed not used files from old implementations.
- Renamed some classes to follow naming convention.
- Renamed methods to use consistent styling.
- Restructured code.

[EGD-6591] Remove excessive logs from USB stack

Removed log entries in conflict with charger driver BSP logs

[EGD-6619] Fix Display backlight switches periodically

Reload pwm duty cycle value after CPU frequency change

[EGD-5748] Remake Cellular flow

This commit remakes cellular data flow
introducing full error propagation.

[EGD-6457] Add power management for USB

When the USB is disconnected, we turn off the peripherals
by going into the suspend bus mode.

[EGD-6355] Adjust MuditaOS to be used with Secure Boot

The start address of the OS image adjusted to comply with HAB
Secure Boot. Proper SNVS initialization performed at system startup.
SNVS drivers updated to most recent version. Image signing can be
performed as a part of build process. See doc/secure_boot.md for
more info.

[EGD-6545] Enable magnetometer LPDCM mode

To be able to reduce the power usage of the phone, magnetometer
has been switched into interrupt driven LPDCM mode. Added some
fixups maintaining current behavior on startup and disabling
the tethering mode

[EGD-6499] Fix audio initialization

Now the peripherals and the audio clocks will be turned on
only when the user is using the audio, which will save energy.

[EGD-6506] Turn on function keys backlight during call

Backlight of function keys are on when call is active.
When call ends, previous backlight mode is restored.

[EGD-6118] BT low power initial implementation

The `Pure`'s power consumption was measured in three variants:
 * BT off
 * BT on (master)
 * BT on (EGD-6118)

Measurement results (respectively):
* idle [mA]:
 ** 78-81
 ** 83-85
 ** 78-81

* BT headphones connected [mA]
 ** -
 ** 85-87
 ** 82-85

* music play [mA] (may be not precise)
 ** 90-100
 ** 98-105
 ** 101-115

[EGD-6431] Add battery charging temperature ranges

Added actions of several cell temperature
ranges according to requirements.