Merge tag 'u-boot-stm32-20230106' of https://gitlab.denx.de/u-boot/custodians/u-boot-stm

- stm32mp: Fix board_get_usable_ram_top(): workaround to avoid issue after the
  commit 777aaaa7 ("common/memsize.c: Fix get_effective_memsize() to check
  for overflow") because the effective DDR effective size is reduce by 4KiB
  and sometime the board hang on boot