feat(sme): add basic SME2 tests

FEAT_SME2 introduces an architectural register ZT0 to support
lookup table feature. This patch ensures that EL3 has
properly enabled the SME2 for use at lower exception levels,
thereby disabling the traps execution at lower exception levels,
when instructions access ZT0 register to EL3.

Signed-off-by: Jayanth Dodderi Chidanand <jayanthdodderi.chidanand@arm.com>
Change-Id: I46d51184b74c1e82c88344530601f2a3c1aee8ea
diff --git a/include/common/test_helpers.h b/include/common/test_helpers.h
index 04b8625..fdc5401 100644
--- a/include/common/test_helpers.h
+++ b/include/common/test_helpers.h
@@ -350,6 +350,14 @@
 		}								\
 	} while (false)
 
+#define SKIP_TEST_IF_SME2_NOT_SUPPORTED()					\
+	do {									\
+		if(!is_feat_sme2_supported()) {					\
+			tftf_testcase_printf("FEAT_SME2 not supported\n");	\
+			return TEST_RESULT_SKIPPED;				\
+		}								\
+	} while (false)
+
 /* Helper macro to verify if system suspend API is supported */
 #define is_psci_sys_susp_supported()	\
 		(tftf_get_psci_feature_info(SMC_PSCI_SYSTEM_SUSPEND)		\