feat(cm): test integrity of el1_ctx registers

* This patch adds support to tsp (BL32) Image, to exercise
  EL1_context registers at S-EL1.

* Adds a SMC function ID "MODIFY_EL1_CTX" to handle EL1_CTX
  registers at S-EL1 and overwrite them.

Signed-off-by: Jayanth Dodderi Chidanand <jayanthdodderi.chidanand@arm.com>
Change-Id: Id4f2b3b748f7bc9e6c9d72a2f03d50aefbfb61cb
diff --git a/include/bl32/tsp/tsp.h b/include/bl32/tsp/tsp.h
index 285bfbe..a63abf1 100644
--- a/include/bl32/tsp/tsp.h
+++ b/include/bl32/tsp/tsp.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2022, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2013-2024, Arm Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -36,12 +36,13 @@
  * Identifiers for various TSP services. Corresponding function IDs (whether
  * fast or yielding) are generated by macros defined below
  */
-#define TSP_ADD		0x2000
-#define TSP_SUB		0x2001
-#define TSP_MUL		0x2002
-#define TSP_DIV		0x2003
+#define TSP_ADD				0x2000
+#define TSP_SUB				0x2001
+#define TSP_MUL				0x2002
+#define TSP_DIV				0x2003
 #define TSP_HANDLE_SEL1_INTR_AND_RETURN	0x2004
-#define TSP_CHECK_DIT	0x2005
+#define TSP_CHECK_DIT			0x2005
+#define TSP_MODIFY_EL1_CTX		0x2006
 
 /*
  * Identify a TSP service from function ID filtering the last 16 bits from the