refactor(stm32mp1): move the MCU security to BL32

Change the MCKPROT control management. Now, the MCU subsystem
is done in the BL32 using the dedicated clock function.
If using OP-TEE, you will need the corresponding commit [1].
This should be integrated in OP-TEE tag 4.2.0.

[1] e07f9212d5 plat-stm32mp1: shared_resource: disable MCKPROT if
    not needed

Signed-off-by: Lionel Debieve <lionel.debieve@st.com>
Change-Id: I59f90ace750aa93f674389f881e2fe14ad334a72
2 files changed