DynamicTablesPkg: GTDT updates for ACPI 6.3

The ACPI 6.3 specification adds support for describing
ARMv8.1 EL2 virtual timers. Update GTDT Generator
to extend this support.

Signed-off-by: Pierre Gondois <pierre.gondois@arm.com>
Reviewed-by: Alexei Fedorov <Alexei.Fedorov@arm.com>
Reviewed-by: Sami Mujawar <sami.mujawar@arm.com>

DynamicTablesPkg/Include/ArmNameSpaceObjects.h

@@ -301,6 +301,12 @@ typedef struct CmArmGenericTimerInfo {
 
   /// The non-secure PL2 timer flags
   UINT32  NonSecurePL2TimerFlags;
+
+  /// GSIV for the virtual EL2 timer
+  UINT32  VirtualPL2TimerGSIV;
+
+  /// Flags for the virtual EL2 timer
+  UINT32  VirtualPL2TimerFlags;
 } CM_ARM_GENERIC_TIMER_INFO;
 
 /** A structure that describes the