feat(plat/st): add STM32MP_UART_PROGRAMMER target

Handle boot from UART with STM32CubeProgammer based on mmap io
for STM32MP15.

Depends-On: Iba84e8dfd67b9f30416efb0f6778e48ba1f75dad
Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
Change-Id: Ibd719dd46a11da78633728675ef6639635b6cf67
6 files changed