fix: map ns buffer only if needed for SMMU tests

Since SMMU based tests are only supported for FVP platform at the
moment, the non-secure memory region used as work buffer for
SMMU test need not be mapped in the page tables for other platforms.

This patch helps to fix a hang noticed for TC based spm test.

Change-Id: I137eeea684250f9620b4e6d585018ad3d62178b4
Signed-off-by: Madhukar Pappireddy <madhukar.pappireddy@arm.com>
diff --git a/spm/cactus/cactus_main.c b/spm/cactus/cactus_main.c
index e0e2c88..b3f7451 100644
--- a/spm/cactus/cactus_main.c
+++ b/spm/cactus/cactus_main.c
@@ -115,8 +115,10 @@
 	/* scratch memory allocated to be used for running SMMU tests */
 	MAP_REGION_FLAT(PLAT_CACTUS_MEMCPY_BASE, PLAT_CACTUS_MEMCPY_RANGE,
 			MT_MEMORY | MT_RW),
+#if PLAT_fvp
 	MAP_REGION_FLAT(PLAT_CACTUS_NS_MEMCPY_BASE, PLAT_CACTUS_MEMCPY_RANGE,
 			MT_MEMORY | MT_RW | MT_NS),
+#endif
 	{0}
 };