feat(spmc): enable building of the SPMC at EL3

Introduce build flag for enabling the secure partition
manager core, SPMC_AT_EL3. When enabled, the SPMC module
will be included into the BL31 image. By default the
flag is disabled.

Signed-off-by: Marc Bonnici <marc.bonnici@arm.com>
Change-Id: I5ea1b953e5880a07ffc91c4dea876a375850cf2a
diff --git a/Makefile b/Makefile
index f91699c..3136887 100644
--- a/Makefile
+++ b/Makefile
@@ -527,6 +527,9 @@
             ifeq ($(CTX_INCLUDE_EL2_REGS),0)
                 $(error SPMD with SPM at S-EL2 requires CTX_INCLUDE_EL2_REGS option)
             endif
+	    ifeq ($(SPMC_AT_EL3),1)
+                $(error SPM cannot be enabled in both S-EL2 and EL3.)
+            endif
         endif
 
         ifeq ($(findstring optee_sp,$(ARM_SPMC_MANIFEST_DTS)),optee_sp)
@@ -577,6 +580,9 @@
 ifneq (${ARCH},aarch64)
 	$(error ENABLE_RME requires AArch64)
 endif
+ifeq ($(SPMC_AT_EL3),1)
+	$(error SPMC_AT_EL3 and ENABLE_RME cannot both be enabled.)
+endif
 include services/std_svc/rmmd/rmmd.mk
 $(warning "RME is an experimental feature")
 endif
@@ -1006,6 +1012,7 @@
         SEPARATE_NOBITS_REGION \
         SPIN_ON_BL1_EXIT \
         SPM_MM \
+        SPMC_AT_EL3 \
         SPMD_SPM_AT_SEL2 \
         TRUSTED_BOARD_BOOT \
         CRYPTO_SUPPORT \
@@ -1138,6 +1145,7 @@
         SPD_${SPD} \
         SPIN_ON_BL1_EXIT \
         SPM_MM \
+        SPMC_AT_EL3 \
         SPMD_SPM_AT_SEL2 \
         TRUSTED_BOARD_BOOT \
         CRYPTO_SUPPORT \