feat(the): add support for FEAT_THE

Arm v8.9 introduces FEAT_THE, adding Translation Hardening Extension
Read-Check-Write mask registers, RCWMASK_EL1 and RCWSMASK_EL1.
Support this, context switching the registers and disabling
traps so lower ELs can access the new registers.

Change the FVP platform to default to handling this as a dynamic option
so the right decision can be made by the code at runtime.

Change-Id: I8775787f523639b39faf61d046ef482f73b2a562
Signed-off-by: Jayanth Dodderi Chidanand <jayanthdodderi.chidanand@arm.com>
Signed-off-by: Govindraj Raja <govindraj.raja@arm.com>
diff --git a/Makefile b/Makefile
index 179e07a..e402a6c 100644
--- a/Makefile
+++ b/Makefile
@@ -1263,6 +1263,7 @@
 	ENABLE_FEAT_RNG_TRAP \
 	ENABLE_FEAT_SEL2 \
 	ENABLE_FEAT_TCR2 \
+	ENABLE_FEAT_THE \
 	ENABLE_FEAT_SB \
 	ENABLE_FEAT_S2PIE \
 	ENABLE_FEAT_S1PIE \
@@ -1419,6 +1420,7 @@
 	ENABLE_FEAT_CSV2_3 \
 	ENABLE_FEAT_PAN \
 	ENABLE_FEAT_TCR2 \
+	ENABLE_FEAT_THE \
 	ENABLE_FEAT_S2PIE \
 	ENABLE_FEAT_S1PIE \
 	ENABLE_FEAT_S2POE \