Adding the MCU hold boot management through a SCMI dedicated
reset domain. Remove the associated RCC SMC service.

Minor: Fix the panic when trying to checking access to avoid
non-secure world panic trigger.

Signed-off-by: Lionel Debieve <lionel.debieve@st.com>
Change-Id: I70fe10602eaa0e76ef2aad9cd8c1b0454dae190a