feat(rdn2): enable MTE2 if present on the platform

MTE2 is an optional feature that could be part of platforms based on Arm
V8.5 or above. If this feature is implemented on the platform, lower ELs
could potentially access the featre registers leading EL3 traps.
Therefore, set MTE2 build option to '2' to enable the feature only if
its implemented on the platform.

Signed-off-by: Rohit Mathew <rohit.mathew@arm.com>
Change-Id: I97c341ac38485937eb18ce9bdcffec26c0e5e76d
diff --git a/plat/arm/board/neoverse_rd/platform/rdn2/platform.mk b/plat/arm/board/neoverse_rd/platform/rdn2/platform.mk
index 6eee3f5..9d771a1 100644
--- a/plat/arm/board/neoverse_rd/platform/rdn2/platform.mk
+++ b/plat/arm/board/neoverse_rd/platform/rdn2/platform.mk
@@ -105,6 +105,7 @@
 
 override CTX_INCLUDE_AARCH32_REGS	:= 0
 override ENABLE_FEAT_AMU		:= 1
+override ENABLE_FEAT_MTE2       	:= 2
 
 # Enable the flag since RD-N2 has a system level cache
 NEOVERSE_Nx_EXTERNAL_LLC		:=	1