stm32mp1: set XN attribute for some areas in BL2

DTB and BL32 area should not be set as executable in MMU during BL2
execution, hence set those areas as MT_RO_DATA.

Change-Id: I87c47a1e7fda761e541ec98a5b294588384d31db
Signed-off-by: Yann Gautier <yann.gautier@st.com>
1 file changed