fix(amu): fault handling on EL2 context switch

The HAFGRTR_EL2 register is UNDEFINED unless the CPU supports both
FEAT_FGT and FEAT_AMUv1. FEAT_FGT is mandatory for v8.6-A and upwards,
but FEAT_AMUv1 is optional (from v8.4-A upwards), and as such any
8.6-A cores today without support for FEAT_AMUv1 will trigger an
undefined instruction exception on accessing this register.

Currently ARM_ARCH_AT_LEAST macro has been used to associate with an
architecture extension allowing to access HAFGRTR_EL2 register. This
condition should be replaced with macros specific to individual
features. This patch adds a new set of macros "ENABLE_FEAT_FGT,
ENABLE_FEAT_AMUv1, ENABLE_FEAT_ECV" under build options to provide
controlled access to the HAFGRTR_EL2 register.

Further to ensure that the the build options passed comply
with the given hardware implementation, a feature detection mechanism,
checking whether build options match with the architecture is required
at bootime. This will be implemented and pushed later in a separate
patch.

Signed-off-by: Jayanth Dodderi Chidanand <jayanthdodderi.chidanand@arm.com>
Change-Id: Ie390f4babe233b8b09455290277edbddecd33ead
diff --git a/include/lib/el3_runtime/aarch64/context.h b/include/lib/el3_runtime/aarch64/context.h
index 698e208..512d196 100644
--- a/include/lib/el3_runtime/aarch64/context.h
+++ b/include/lib/el3_runtime/aarch64/context.h
@@ -207,8 +207,8 @@
 #define CTX_MPAMVPMV_EL2	U(0x158)
 
 // Starting with Armv8.6
-#define CTX_HAFGRTR_EL2		U(0x160)
-#define CTX_HDFGRTR_EL2		U(0x168)
+#define CTX_HDFGRTR_EL2		U(0x160)
+#define CTX_HAFGRTR_EL2		U(0x168)
 #define CTX_HDFGWTR_EL2		U(0x170)
 #define CTX_HFGITR_EL2		U(0x178)
 #define CTX_HFGRTR_EL2		U(0x180)