fix(rme): do not trap access to MPAM system registers in Realm mode

Change-Id: I77496ee962727687b28f71a1a15b4fe4133c613c
Signed-off-by: Javier Almansa Sobrino <javier.almansasobrino@arm.com>
diff --git a/Makefile b/Makefile
index eca70bd..aae3452 100644
--- a/Makefile
+++ b/Makefile
@@ -581,6 +581,10 @@
 	CTX_INCLUDE_AARCH32_REGS := 0
 	CTX_INCLUDE_PAUTH_REGS := 1
 
+	ifneq ($(ENABLE_FEAT_MPAM), 0)
+		CTX_INCLUDE_MPAM_REGS := 1
+	endif
+
 	# RME enables CSV2_2 extension by default.
 	ENABLE_FEAT_CSV2_2 = 1
 endif #(FEAT_RME)