BL32/SP_MIN configures platform security hardening from the shared
resources driver.  At the end of SP_MIN initialization, all shared
resources shall be assigned to secure or non-secure world by
drivers. A lock prevent from further change on the resource
assignation. By definition, resources not registered are assign
to non-secure world since not claimed by any component on the BL.

No functional change as all resources are currently in state
SHRES_UNREGISTERED hence assigned to non-secure world as prior
this change in stm32mp1_etzpc_early_setup() and
sp_min_platform_setup().

Change-Id: Ic41fab47216c3b8b7a6a75b8358cfcec411ed941
Signed-off-by: Etienne Carriere <etienne.carriere@st.com>