Vlv2TbltDevicePkg: Add /y flag to generate report files

https://bugzilla.tianocore.org/show_bug.cgi?id=273

Update build script to generate a report file and put
both the report file and the log file in the directory
Vlv2TbltDevicePkg with an EDK2_Vlv2TbltDevicePkg prefix.

Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: David Wei <david.wei@intel.com>
Cc: Mang Guo <mang.guo@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Michael Kinney <michael.d.kinney@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>

Vlv2TbltDevicePkg/Build_IFWI.bat

@@ -40,6 +40,11 @@ if /i "%~1"=="/l" (
     shift
     goto OptLoop
 )
+if /i "%~1"=="/y" (
+    set Build_Flags=%Build_Flags% /y
+    shift
+    goto OptLoop
+)
 if /i "%~1" == "/c" (
     set Build_Flags=%Build_Flags% /c
     shift