Platforms/ARM: FVP: Add optional GICv3 with v2 Legacy support

GICv3 with v2 legacy support was removed, but this patch adds it back in
conditionally.

The default continues to use GICv3 natively unless specifically
requested at build time by defining "ARM_FVP_GICV3_WITH_V2_LEGACY".

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ryan Harkin <ryan.harkin@linaro.org>
diff --git a/Platforms/ARM/VExpress/ArmVExpress-FVP-AArch64.dsc b/Platforms/ARM/VExpress/ArmVExpress-FVP-AArch64.dsc
index b2a1f64..9832f02 100644
--- a/Platforms/ARM/VExpress/ArmVExpress-FVP-AArch64.dsc
+++ b/Platforms/ARM/VExpress/ArmVExpress-FVP-AArch64.dsc
@@ -79,6 +79,10 @@
   #  It could be set FALSE to save size.

   gEfiMdeModulePkgTokenSpaceGuid.PcdConOutGopSupport|TRUE

 

+!ifdef ARM_FVP_GICV3_WITH_V2_LEGACY

+  gArmTokenSpaceGuid.PcdArmGicV3WithV2Legacy|TRUE

+!endif

+

 [PcdsFixedAtBuild.common]

   gArmPlatformTokenSpaceGuid.PcdFirmwareVendor|"ARM Fixed Virtual Platform"

   gEmbeddedTokenSpaceGuid.PcdEmbeddedPrompt|"ARM-FVP"