Include the missing Guid header file to refer the global Guid

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@7498 6f19259b-4bc3-4df7-8a09-765794883524

MdeModulePkg/Universal/PCD/Dxe/Service.h

@@ -16,6 +16,7 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
 #define _PCD_DXE_SERVICE_H_
 
 #include <PiDxe.h>
+#include <Guid/PcdDataBaseHobGuid.h>
 #include <Protocol/Pcd.h>
 #include <Library/BaseLib.h>
 #include <Library/DebugLib.h>
@@ -1057,8 +1058,6 @@ SetPtrTypeSize (
   IN    OUT   UINTN             *CurrentSize
   );
 
-extern EFI_GUID gPcdDataBaseHobGuid;
-
 extern PCD_DATABASE * mPcdDatabase;
 
 extern DXE_PCD_DATABASE_INIT gDXEPcdDbInit;