qemu_v8: support for FF-A in Xen

Adds support in Xen configuration to recognize if compiling for FF-A.

Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
Acked-by: Jerome Forissier <jerome.forissier@linaro.org>
diff --git a/qemu_v8.mk b/qemu_v8.mk
index 6c2bac6..b42cc85 100644
--- a/qemu_v8.mk
+++ b/qemu_v8.mk
@@ -417,6 +417,9 @@
 ################################################################################
 
 XEN_CONFIGS = .config $(ROOT)/build/kconfigs/xen.conf
+ifneq ($(filter 1 2 3,$(SPMC_AT_EL)),)
+XEN_FFA = y
+endif
 
 $(XEN_PATH)/xen/.config:
 	$(MAKE) -C $(XEN_PATH)/xen XEN_TARGET_ARCH=arm64 defconfig
@@ -536,6 +539,7 @@
 		export QEMU_CPU=$(QEMU_CPU) && \
 		export QEMU_VIRT=$(QEMU_VIRT) && \
 		export XEN_BOOT=$(XEN_BOOT) && \
+		export XEN_FFA=$(XEN_FFA) && \
 		expect $(ROOT)/build/qemu-check.exp -- $(check-args) || \
 		(if [ "$(DUMP_LOGS_ON_ERROR)" ]; then \
 			echo "== $$PWD/serial0.log:"; \