feat(stm32mp2): add FWU support

Add stm32_get_bkpr_fwu_info_addr() function.
Call stm32_fwu_set_boot_idx() in bl2_plat_handle_post_image_load().

Signed-off-by: Yann Gautier <yann.gautier@foss.st.com>
Change-Id: Ieb57dffa4ce784d1ed61b401dc17376fe745c111
2 files changed