arm: stm32mp: add boot_mode support for STM32MP25

Add support of all the boot mode supported by STM32MP25x family
with information provided by TF-A in backup register

Signed-off-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
Signed-off-by: Patrice Chotard <patrice.chotard@foss.st.com>
3 files changed