Revert "DynamicTablesPkg: Rename enum used for ID Mapping"

This reverts commit 1d49a75367.

Reverting this patch as Soft Feature Freeze for
edk2-stable201903 started on 22 Feb 2019.

Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Alexei Fedorov <alexei.fedorov@arm.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Sami Mujawar <sami.mujawar@arm.com>
Reviewed-by: Alexei Fedorov <alexei.fedorov@arm.com>

DynamicTablesPkg/Include/ArmNameSpaceObjects.h

@@ -52,7 +52,7 @@ typedef enum ArmObjectID {
   EArmObjSmmuV3,                      ///< 22 - SMMUv3
   EArmObjPmcg,                        ///< 23 - PMCG
   EArmObjGicItsIdentifierArray,       ///< 24 - GIC ITS Identifier Array
-  EArmObjIdMappingArray,              ///< 25 - ID Mapping Array
+  EArmObjIdMapping,                   ///< 25 - ID Mapping
   EArmObjSmmuInterruptArray,          ///< 26 - SMMU Interrupt Array
   EArmObjMax
 } EARM_OBJECT_ID;