After calling HAL_SYSTICK_Config the SysTick IRQ priority is set to 15, the
lowest priority. This commit reconfigures the IRQ priority to the desired
TICK_INT_PRIORITY value.
To use HSE bypass mode the board should define:
#define MICROPY_HW_CLK_USE_BYPASS (1)
If this is not defined, or is defined to 0, then HSE oscillator mode is
used.
The CMSIS files for the STM32 range provide macros to distinguish between
the different MCU series: STM32F4, STM32F7, STM32H7, STM32L4, etc. Prefer
to use these instead of custom ones.
This is to keep the top-level directory clean, to make it clear what is
core and what is a port, and to allow the repository to grow with new ports
in a sustainable way.