refactor(qemu): handle SPM_MM builds

SPM_MM is not compatible with ENABLE_SVE_FOR_NS and breaks build early:

> Including SPM Management Mode (MM) makefile
> services/std_svc/spm/spm_mm/spm_mm.mk:14: *** "Error: SPM_MM is not compatible with ENABLE_SVE_FOR_NS". Stop.

Signed-off-by: Marcin Juszkiewicz <marcin.juszkiewicz@linaro.org>
Change-Id: Iabe181647fce00a432ae11dc4599b71619364c24
diff --git a/plat/qemu/common/common.mk b/plat/qemu/common/common.mk
index 947c05c..9d5e647 100644
--- a/plat/qemu/common/common.mk
+++ b/plat/qemu/common/common.mk
@@ -74,12 +74,18 @@
 				${QEMU_GIC_SOURCES}
 
 # CPU flag enablement
+ifeq (${ARCH},aarch64)
 
 # Later QEMU versions support SME and SVE.
-ifeq (${ARCH},aarch64)
+# SPM_MM is not compatible with ENABLE_SVE_FOR_NS (build breaks)
+ifeq (${SPM_MM},1)
+	ENABLE_SVE_FOR_NS	:= 0
+	ENABLE_SME_FOR_NS	:= 0
+else
 	ENABLE_SVE_FOR_NS	:= 2
 	ENABLE_SME_FOR_NS	:= 2
 endif
+endif
 
 # QEMU will use the RNDR instruction for the stack protector canary.
 ENABLE_FEAT_RNG			:= 2