Enable ICACHE, LPTICKER, TRNG and WATCHDOG for STM32H5

[wdx04]

Summary of changes

Enables ICACHE, LPTICKER, TRNG and WATCHDOG features for the STM32H5 family.
MPU Region 5 is used to avoid hardfaults when ICACHE is enabled:
https://community.st.com/t5/stm32-mcus/how-to-avoid-a-hardfault-when-icache-is-enabled-on-the-stm32h5/ta-p/630085

Impact of changes

Migration actions required

Documentation

None

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Pull request type

[X] Patch update (Bug fix / Target update / Docs update / Test update / Refactor)
[] Feature update (New feature / Functionality change / New API)
[] Major update (Breaking change E.g. Return code change / API behaviour change)

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Test results

[] No Tests required for this change (E.g docs only update)
[] Covered by existing mbed-os tests (Greentea or Unittest)
[X] Tests / results supplied as part of this PR

I run GreenTea tests on a NUCLEO-H563ZI board and passed the LPTICKER, TRNG and WATCHDOG tests.
The hal-sleep test failed when LPTICKER is used as wakup source from deepsleep mode, but it seems unrelated to LPTICKER itself: even if I comment out the code that setup the LPTICKER interrupt, the system will still wake up from deepsleep mode after 309 ticks. The netsocket related tests failed with Hard Faults. I'm not sure how to setup the test environments for netsocket tests or skip them.

greentea-log-nucleo-h563zi.txt

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[multiplemonomials]

system_clock.c feels like the wrong location to put this. Could we create a new .c file for this under TARGET_STM32H5, and then call the function from SystemInit() in TARGET_STM32H5/STM32Cube_FW/system_stm32h5xx.c?

[multiplemonomials]

I can test this on my end to see what's up with the Ethernet tests.