BaseTools: Fix a ParseDevPathValue function issue.

In ParseDevPathValue, the binary data need to convert to string
for python3 and python2 compatiblity.

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>

BaseTools/Source/Python/Common/Misc.py

@@ -1032,6 +1032,7 @@ def ParseFieldValue (Value):
             p.stderr.close()
         if err:
             raise BadExpression("DevicePath: %s" % str(err))
+        out = out.decode()
         Size = len(out.split())
         out = ','.join(out.split())
         return '{' + out + '}', Size