BaseTools: Support multiple .h file

for structure Pcd declaration in DEC file.

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Bob Feng <bob.c.feng@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>
(cherry picked from commit 81add864f4)

BaseTools/Source/Python/Workspace/BuildClassObject.py

@@ -115,7 +115,7 @@ class StructurePcd(PcdClassObject):
         if validlists is None: validlists=[]
         if expressions is None : expressions=[]
         super(StructurePcd, self).__init__(Name, Guid, Type, DatumType, Value, Token, MaxDatumSize, SkuInfoList, IsOverrided, GuidValue, validateranges, validlists, expressions)
-        self.StructuredPcdIncludeFile = StructuredPcdIncludeFile
+        self.StructuredPcdIncludeFile = [] if StructuredPcdIncludeFile is None else StructuredPcdIncludeFile
         self.PackageDecs = Packages
         self.DefaultStoreName = [default_store]
         self.DefaultValues = collections.OrderedDict({})