Vlv2TbltDevicePkg: Fix build scripts

https://bugzilla.tianocore.org/show_bug.cgi?id=911

Update build scripts to work with edk2 and Vlv2Binaries
in PACKAGES_PATH.

Cc: David Wei <david.wei@intel.com>
Cc: Mang Guo <mang.guo@intel.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Michael D Kinney <michael.d.kinney@intel.com>
Reviewed-by: David Wei <david.wei@intel.com>
Reviewed-by: Guo Mang <mang.guo@intel.com>

Vlv2TbltDevicePkg/Build_IFWI.bat

@@ -1,7 +1,7 @@
 @REM @file
 @REM   Windows batch file to build BIOS ROM
 @REM
-@REM Copyright (c) 2006 - 2014, Intel Corporation. All rights reserved.<BR>
+@REM Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>
 @REM This program and the accompanying materials
 @REM are licensed and made available under the terms and conditions of the BSD License
 @REM which accompanies this distribution.  The full text of the license may be found at
@@ -131,11 +131,11 @@ if %ERRORLEVEL% NEQ 0 (
 echo.
 echo Finished Building BIOS.
 @REM Set BIOS_ID environment variable here.
-call Conf\BiosId.bat
+call %WORKSPACE%\Conf\BiosId.bat
 echo BIOS_ID=%BIOS_ID%
 
 :: Set the Board_Id, Build_Type, Version_Major, and Version_Minor environment variables
-find /v "#" Conf\BiosId.env > ver_strings
+find /v "#" %WORKSPACE%\Conf\BiosId.env > ver_strings
 for /f "tokens=1,3" %%i in (ver_strings) do set %%i=%%j
 del /f/q ver_strings >nul
 set BIOS_Name=%BOARD_ID%_%Arch%_%BUILD_TYPE%_%VERSION_MAJOR%_%VERSION_MINOR%.ROM
@@ -149,7 +149,7 @@ if "%Platform_Type%" == "BYTC" (
     pushd %PLATFORM_PACKAGE%\Stitch
 )
    :: IFWIStitch.bat [/nG] [/nM] [/nB] [/B BIOS.rom] [/C StitchConfig] [/S IFWISuffix]
-   call IFWIStitch.bat %Stitch_Flags% /B ..\..\%BIOS_Name% %IFWI_Suffix%
+   call IFWIStitch.bat %Stitch_Flags% /B %WORKSPACE%\%BIOS_Name% %IFWI_Suffix%
    
    @echo off
 popd