feat(debugv8p9): test if EL3 has properly enabled FEAT_Debugv8p9

When FEAT_Debugv8p9 is not enabled, access to MDSELR_EL1
traps to EL3. Access to FEAT_DEBUGV8P9 control registers
must be explicitly enabled in EL3,

This testcase uses this behavior to test if
FEAT_Debugv8p9 is enabled or not.

Change-Id: I2f9a0158e9f38eaffac2e27c40d44d3c520d508d
Signed-off-by: Arvind Ram Prakash <arvind.ramprakash@arm.com>
diff --git a/include/common/test_helpers.h b/include/common/test_helpers.h
index 8cddc72..ced1745 100644
--- a/include/common/test_helpers.h
+++ b/include/common/test_helpers.h
@@ -115,6 +115,16 @@
 		}								\
 	} while (0)
 
+#define SKIP_TEST_IF_DEBUGV8P9_NOT_SUPPORTED()					\
+	do {									\
+		if (arch_get_debug_version() != 				\
+				ID_AA64DFR0_V8_9_DEBUG_ARCH_SUPPORTED) {	\
+			tftf_testcase_printf(					\
+				"Debugv8p9 not supported\n");			\
+			return TEST_RESULT_SKIPPED;				\
+		}								\
+	} while (0)
+
 #define SKIP_TEST_IF_SVE_NOT_SUPPORTED()					\
 	do {									\
 		if (!is_armv8_2_sve_present()) {				\