feat(mte): add mte2 feat

Add support for feat mte2. tfsr_el2 is available only with mte2,
however currently its context_save/restore is done with mte rather than
mte2, so introduce 'is_feat_mte2_supported' to check mte2.

Change-Id: I108d9989a8f5b4d1d2f3b9865a914056fa566cf2
Signed-off-by: Govindraj Raja <govindraj.raja@arm.com>
diff --git a/bl32/tsp/tsp_main.c b/bl32/tsp/tsp_main.c
index b8d336f..d8031f9 100644
--- a/bl32/tsp/tsp_main.c
+++ b/bl32/tsp/tsp_main.c
@@ -238,13 +238,13 @@
 	service_arg0 = (uint64_t)service_args;
 	service_arg1 = (uint64_t)(service_args >> 64U);
 
-#if ENABLE_FEAT_MTE
 	/*
 	 * Write a dummy value to an MTE register, to simulate usage in the
 	 * secure world
 	 */
-	write_gcr_el1(0x99);
-#endif
+	if (is_feat_mte_supported()) {
+		write_gcr_el1(0x99);
+	}
 
 	/* Determine the function to perform based on the function ID */
 	switch (TSP_BARE_FID(func)) {