memory: stm32-fmc2-ebi: add MP25 RIF support

memory: stm32-fmc2-ebi: add MP25 RIF support

The FMC2 revision 2 supports security and isolation compliant with
the Resource Isolation Framework (RIF). From RIF point of view,
the FMC2 is composed of several independent resources, listed below,
which can be assigned to different security and compartment domains:
 - 0: Common FMC_CFGR register.
 - 1: EBI controller for Chip Select 1.
 - 2: EBI controller for Chip Select 2.
 - 3: EBI controller for Chip Select 3.
 - 4: EBI controller for Chip Select 4.
 - 5: NAND controller.

Signed-off-by: Christophe Kerello <christophe.kerello@foss.st.com>
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>