RFC: Add PPU flop reset

[Gert Wollny]

This series adds running the PPU flop reset which is required for some
hardware. This implementation was tested with the STM vendor kernel based on 
linux-6.6.48 and that is provided with 
  https://github.com/STMicroelectronics/oe-manifest/
  Release: openstlinux-6.6-yocto-scarthgap-mpu-v25.04.30

The command stream is based on the stream that is emitted in the acccording 
code of the galcore kernel. Since I have only a stm32mp257f-ev1 board to
test this for all parts that are emitted conditionally in the galcore kernel
only the part that is required for this board is submitted here. 

Thanks for any comments, 
Gert