Add machine-level support for STM32U5 family: GPIO ports A-I with clock
enables via AHB2ENR1, EXTI pin interrupts (individual EXTI0-15 IRQs),
timer definitions (TIM1-8, TIM15-17), RNG, and alternate function clock
enables for all peripherals.
Add UART support with STM32U585 baud rate and register configuration.
Add arduino-uno-q board pin definitions and USART2 serial.
Update shared build tags: gpio_revb, gpio_reva, exti_exti, exti_syscfg.
Do it all at once in preparation for Go 1.18 support.
To make this commit, I've simply modified the `fmt-check` Makefile
target to rewrite files instead of listing the differences. So this is a
fully mechanical change, it should not have introduced any errors.
deadprogram
Yurii Soldak
sago35
Ayke van Laethem
Kenneth Bell