drivers: st: update drivers code

Reword some traces.
Use uintptr_t where required.
Reduce scope of variables.
Improve io_stm32image algo.
Complete some IP registers definitions.
Add failure on supported DDR (stm32mp1_ddr_init()).
Fix cache flush on cache disable (stm32mp1_ddr_setup).

Change-Id: Ie02fa71e02b9d69abc807fd5b7df233e5be6668c
Signed-off-by: Yann Gautier <yann.gautier@st.com>
Signed-off-by: Etienne Carriere <etienne.carriere@st.com>
Signed-off-by: Lionel Debieve <lionel.debieve@st.com>
Signed-off-by: Nicolas Le Bayon <nicolas.le.bayon@st.com>
Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>