BaseTools:Run packagedoc_cli.py to generate doc failed

The reason for this problem is that the file was opened incorrectly.

Cc: Bob Feng <bob.c.feng@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Zhiju.Fan <zhijux.fan@intel.com>
Reviewed-by: Bob Feng <bob.c.feng@intel.com>

BaseTools/Scripts/PackageDocumentTools/plugins/EdkPlugins/edk2/model/doxygengen.py

@@ -376,9 +376,10 @@ class PackageDocumentAction(DoxygenAction):
             return
 
         try:
-            f = open(path, 'r')
-            lines = f.readlines()
-            f.close()
+            with open(path, 'r') as f:
+                lines = f.readlines()
+        except UnicodeDecodeError:
+            return
         except IOError:
             ErrorMsg('Fail to open file %s' % path)
             return