BaseTools: Extend the keyword "!include"/"!if" to case-insensitive

Extend the keyword "!include", "!if", etc to case-insensitive.
Current DSC parser already support it, while FDF parser only support
the lower case, so this patch add the support for FDF parser.

Fixes: https://bugzilla.tianocore.org/show_bug.cgi?id=1111
Cc: Liming Gao <liming.gao@intel.com>
Cc: Yonghong Zhu <yonghong.zhu@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Zhiju.Fan <zhijux.fan@intel.com>
Reviewed-by: Yonghong Zhu <yonghong.zhu@intel.com>
diff --git a/BaseTools/Source/Python/GenFds/FdfParser.py b/BaseTools/Source/Python/GenFds/FdfParser.py
index 8de0b48..7e1be65 100644
--- a/BaseTools/Source/Python/GenFds/FdfParser.py
+++ b/BaseTools/Source/Python/GenFds/FdfParser.py
@@ -1113,6 +1113,8 @@
         if self.CurrentLineNumber != StartLine:

             EndPos = len(self.Profile.FileLinesList[StartLine-1])

         self.__Token = self.Profile.FileLinesList[StartLine-1][StartPos : EndPos]

+        if self.__Token.lower() in [TAB_IF, TAB_END_IF, TAB_ELSE_IF, TAB_ELSE, TAB_IF_DEF, TAB_IF_N_DEF, TAB_ERROR, TAB_INCLUDE]:

+            self.__Token = self.__Token.lower()

         if StartPos != self.CurrentOffsetWithinLine:

             return True

         else: