refactor(qemu): handle AArch64 flags

Handle coherency in one place for AArch64 mode.

Change-Id: Id3678a8f478e5ef731c81c0df30059000e380758
Signed-off-by: Marcin Juszkiewicz <marcin.juszkiewicz@linaro.org>
diff --git a/plat/qemu/common/common.mk b/plat/qemu/common/common.mk
index bb88dcc..947c05c 100644
--- a/plat/qemu/common/common.mk
+++ b/plat/qemu/common/common.mk
@@ -86,3 +86,16 @@
 
 # QEMU 7.2+ has support for FGT and Linux needs it enabled to boot on max
 ENABLE_FEAT_FGT			:= 2
+
+ifeq (${ARCH},aarch64)
+# Treating this as a memory-constrained port for now
+USE_COHERENT_MEM	:=	0
+
+# This can be overridden depending on CPU(s) used in the QEMU image
+HW_ASSISTED_COHERENCY	:=	1
+
+CTX_INCLUDE_AARCH32_REGS := 0
+ifeq (${CTX_INCLUDE_AARCH32_REGS}, 1)
+$(error "This is an AArch64-only port; CTX_INCLUDE_AARCH32_REGS must be disabled")
+endif
+endif