feat(tc): allow TARGET_VERSION=4

Add basic support for TARGET_VERSION=4. It extends the existing 'if'
statements in the Makefile and the header to allow them to take the
value of 4 and also specifies the SCMI platform info to use for TC4.

Change-Id: I8d8257671314277a133e88ef65fae8fada93d00e
Signed-off-by: Jackson Cooper-Driver <jackson.cooper-driver@arm.com>
Signed-off-by: Leo Yan <leo.yan@arm.com>
diff --git a/plat/arm/board/tc/include/tc_helpers.S b/plat/arm/board/tc/include/tc_helpers.S
index 29130ea..9adf09a 100644
--- a/plat/arm/board/tc/include/tc_helpers.S
+++ b/plat/arm/board/tc/include/tc_helpers.S
@@ -81,6 +81,10 @@
 	ret
 endfunc TC_HANDLER(3)
 
+func TC_HANDLER(4)
+	ret
+endfunc TC_HANDLER(4)
+
 	/* -----------------------------------------------------
 	 * void plat_reset_handler(void);
 	 * -----------------------------------------------------