Fix clocking configuration issues on STM32H7x processors

[megacct]

Hi, could someone provide some background / insight into why the clocking / voltage issues identified and fixed by:

mbed-ce/mbed-os#262

and then adopted by

ARMmbed/mbed-os#15502

have not been applied to the Arduino fork of mbed-os?

Update: Having looked through these PRs, the undervolting issue appears unaddressed and is concerning me.