edksetup.bat: Support --nt32 X64

Support --nt32 X64 for building 64-bit NT32.
For setting up Windows environment variables requited by NT32, follow the
same approach as Edk2Setup.bat by using the get_vsvars.bat and
SetVisualStudio.bat.

Sync the help text of NT32 with Edk2Setup.bat.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Cinnamon Shia <cinnamon.shia@hpe.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>

BaseTools/toolsetup.bat

@@ -4,6 +4,7 @@
 @REM   if the file is not executed within a WORKSPACE\BaseTools folder.
 @REM
 @REM Copyright (c) 2006 - 2013, Intel Corporation. All rights reserved.<BR>
+@REM (C) Copyright 2016 Hewlett Packard Enterprise Development LP<BR>
 @REM
 @REM This program and the accompanying materials are licensed and made available
 @REM under the terms and conditions of the BSD License which accompanies this 
@@ -33,6 +34,9 @@ if /I "%1"=="/?" goto Usage
 :loop
   if "%1"=="" goto setup_workspace
   if /I "%1"=="--nt32" (
+    if /I "%2" == "X64" (
+      shift
+    )
     @REM Ignore --nt32 flag
     shift
     goto loop