fix(sme): align SME test vector arrays to 16 bytes

SME test vectors need 16 bytes alignment for the related
instructions to work properly.

Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
Change-Id: Ifd5db7a3536d4b26f9922d1a0bfb09351c4fa6ab
diff --git a/tftf/tests/extensions/sme/test_sme.c b/tftf/tests/extensions/sme/test_sme.c
index 58690ea..64391ab 100644
--- a/tftf/tests/extensions/sme/test_sme.c
+++ b/tftf/tests/extensions/sme/test_sme.c
@@ -17,10 +17,9 @@
 #ifdef __aarch64__
 
 /* Global buffers*/
-static uint64_t ZA_In_vector[8] = {0xaaff, 0xbbff, 0xccff, 0xddff, 0xeeff,
+static __aligned(16) uint64_t ZA_In_vector[8] = {0xaaff, 0xbbff, 0xccff, 0xddff, 0xeeff,
 					0xffff, 0xff00, 0xff00};
-static uint64_t ZA_Out_vector[8] = {0};
-
+static __aligned(16) uint64_t ZA_Out_vector[8] = {0};
 
 /**
  * sme_zero_ZA