Enable v8.6 AMU enhancements (FEAT_AMUv1p1)

ARMv8.6 adds virtual offset registers to support virtualization of the
event counters in EL1 and EL0.  This patch enables support for this
feature in EL3 firmware.

Signed-off-by: John Powell <john.powell@arm.com>
Change-Id: I7ee1f3d9f554930bf5ef6f3d492e932e6d95b217
diff --git a/Makefile b/Makefile
index f899dac..b6c8b21 100644
--- a/Makefile
+++ b/Makefile
@@ -895,6 +895,7 @@
         DYN_DISABLE_AUTH \
         EL3_EXCEPTION_HANDLING \
         ENABLE_AMU \
+        AMU_RESTRICT_COUNTERS \
         ENABLE_ASSERTIONS \
         ENABLE_MPAM_FOR_LOWER_ELS \
         ENABLE_PIE \
@@ -984,6 +985,7 @@
         DECRYPTION_SUPPORT_${DECRYPTION_SUPPORT} \
         DISABLE_MTPMU \
         ENABLE_AMU \
+        AMU_RESTRICT_COUNTERS \
         ENABLE_ASSERTIONS \
         ENABLE_BTI \
         ENABLE_MPAM_FOR_LOWER_ELS \