UefiCpuPkg/MpInitLib: Use NASM struc to avoid hardcode offset

In Windows environment, "dumpbin /disasm" is used to verify the
disassembly before and after using NASM struc doesn't change.

Signed-off-by: Ray Ni <ray.ni@intel.com>
Reviewed-by: Eric Dong <eric.dong@intel.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>

UefiCpuPkg/Library/MpInitLib/DxeMpInitLib.inf

@@ -1,7 +1,7 @@
 ## @file
 #  MP Initialize Library instance for DXE driver.
 #
-#  Copyright (c) 2016 - 2020, Intel Corporation. All rights reserved.<BR>
+#  Copyright (c) 2016 - 2021, Intel Corporation. All rights reserved.<BR>
 #  SPDX-License-Identifier: BSD-2-Clause-Patent
 #
 ##
@@ -22,14 +22,13 @@
 #
 
 [Sources.IA32]
-  Ia32/MpEqu.inc
   Ia32/MpFuncs.nasm
 
 [Sources.X64]
-  X64/MpEqu.inc
   X64/MpFuncs.nasm
 
 [Sources.common]
+  MpEqu.inc
   DxeMpLib.c
   MpLib.c
   MpLib.h