CPU migration to stm32h7

[jordens]

@gkasprow could you check whether we can drop in the stm32h7 we have on thermostat_eem and stabilizer? That would reduce the code footprint, simplify maintenance and also enable more population variants/supply chain workarounds.

It should be doable without too much hassle:

https://www.st.com/en/microcontrollers-microprocessors/stm32h7-series.html :

The STM32H7 single-core and value lines are pin-to-pin compatible with the STM32F7 series of very high-performance MCUs and STM32F4 series of high-performance MCUs for the most common packages (*).

https://www.st.com/content/ccc/resource/technical/document/application_note/73/76/21/47/ef/d0/4c/16/DM00164538.pdf/files/DM00164538.pdf/jcr:content/translations/en.DM00164538.pdf
https://www.st.com/resource/en/application_note/dm00337702-migration-of-microcontroller-applications-from-stm32f7-series-to-stm32h743753-line-stmicroelectronics.pdf

[gkasprow]

This particular chip has a different placement of ADC channels, but from hw perspective, it's fine
they also differ by the placement of SPI NSS pins but for SPI peripherals that we don't use here

[jordens]

IIRC there may also be some minor jumpering needed around the analog/digital suplies and references.