core: STM32 H5 support

[PhilippMolitor]

The STM32 H503 chip is one of the newest releases by ST.
There already is a (almost) pin-compatible BlackPill board for this MCU: https://github.com/WeActStudio/WeActStudio.STM32H503CoreBoard

I think this chip might come up in the future for 3d printer electronics boards, as it is a good value for medium to high performance. Also this lays the foundation for STM32H562, which is basically the same with more IO and larger ram/flash (not relevant for klipper).

I already added the CMSIS files and some define guards to correct for some renamed register names. I could use some help for the functions in src/stm32/stm32h5.c, as I do not know much about the initialization and important registers of the STM32 platform.
Additional work will be needed for some of the common peripheral files in the src/stm32 folder.

PR Checklist

• pr title makes sense
• squashed to 1 commit
• added a test case if possible
• if new feature, added to the readme
• ci is happy and green

H5(03) Checklist

• Import all needed CMSIS files
• Add Cortex M33 support
• Add MPU ARM v8
• Add to Kconfig
• Add to STM32 Makefile
• Validate Makefile includes
• Implement entrypoint and helpers src/stm32/stm32h5.c
  • lookup_clock_line()
  • get_pclock_frequency()
  • gpio_clock_enable()
  • bootloader_request()
  • clock_setup()
  • armcm_main()
• Check USB code src/stm32/usbfs.c
• Check ADC peripheral code src/stm32/adc.c
• Check CAN peripheral code src/stm32/can.c
• Check FDCAN peripheral code src/stm32/fdcan.c
• Check SPI peripheral code src/stm32/spi.c
• Check Hardware PWM peripheral code src/stm32/hard_pwm.c
• Check DFU reboot code src/stm32/dfu_reboot.c
• Bootloader offsets?
• Compile test file

H562 Checklist

• Add H562 CMSIS files
• Kconfig, Makefile
• Bootloader offsets?
• Additional IOs and their definitions for the peripherals
• Compile test file