1200: feat(stm32): Add 16 data bit fmc ctor r=Dirbaio a=rmja
This has been validated with the Is42s16400j sdram on stm32f429.
Co-authored-by: Rasmus Melchior Jacobsen <rmja@laesoe.org>
- Move Interrupt and InterruptExecutor from `embassy` to `embassy-cortex-m`.
- Move Unborrow from `embassy` to `embassy-hal-common` (nothing in `embassy` requires it anymore)
- Move PeripheralMutex from `embassy-hal-common` to `embassy-cortex-m`.