enable LittleFS and encryption on STM32 platform (wio-e5)

[dchokola]

• Drop FreeRTOS dependency
  • LittleFS was using FreeRTOS locking functions and malloc()/free()
• LittleFS works
  • properly unlock/lock the FLASH for erasing/writing; fix computation of block sizes
  • mutex functions no-opped
  • malloc()/free() implementations from stdlib
• PKI works
  • depend on latest Crypto library from @caveman99 to make use of STM32 RNG

[CLAassistant]

All committers have signed the CLA.

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you all sign our Contributor License Agreement before we can accept your contribution.
1 out of 2 committers have signed the CLA.

:white_check_mark: caveman99
:x: dchokola
_{You have signed the CLA already but the status is still pending? Let us recheck it.}

[markbirss]

@dchokola tested ok wio-e5, also able with some modification to get rak3172 working