* Add support for MCU = STM32F446
* Update platforms/chibios/GENERIC_STM32_F446XE/configs/config.h
Co-authored-by: Nick Brassel <nick@tzarc.org>
* Restore mcuconf.h to the one used by RT-STM32F446RE-NUCLEO64
* stm32f446: update mcuconf.h and board.h for 16MHz operation, with USB enabled, and other peripherals disabled.
Co-authored-by: Nick Brassel <nick@tzarc.org>