When doing so, do not disbale GPIO clocks as they may be used by other
drivers !
As a result, debug will be disabled by default, but can be enabled by
either modifying code or selecting MBED debug profile.
Review HSE clock initialization to match with latest CUBE firmware.
Also there is no need to set the full clock tree again after deep sleep exit.
With this change we get a stable deep sleep mode (when allowed by CORDIO stack).
These files are not BLE specific, but also needed for some clock setting
for instance.
In order to compile an MBED2 application, we need to move the files.
- move hw_conf.h file to targets/TARGET_STM/TARGET_STM32WB directory as
this is used also out of BLE feature.
- create a dedicated hal_deepsleep function as the behavior in WB is a lot
different from other existing STM32 targets
- update clock tree configuration to directly clock the entire tree @ 32MHz
out of HSE. This is needed as we want to let the M0 core running without
any change on M0-side of clocks when M4 enters /exits deep sleep.