Add MSA optimized ARGB scaling functions

libyuv.gypi

 # Copyright 2014 The LibYuv Project Authors. All rights reserved.
 #
 # Use of this source code is governed by a BSD-style license
 # that can be found in the LICENSE file in the root of the source
 # tree. An additional intellectual property rights grant can be found
 # in the file PATENTS. All contributing project authors may
 # be found in the AUTHORS file in the root of the source tree.
 
 {
   'variables': {
@@ skipping 54 matching lines @@
       'source/row_msa.cc',
       'source/row_neon.cc',
       'source/row_neon64.cc',
       'source/row_win.cc',
       'source/scale.cc',
       'source/scale_any.cc',
       'source/scale_argb.cc',
       'source/scale_common.cc',
       'source/scale_gcc.cc',
       'source/scale_mips.cc',
+      'source/scale_msa.cc',
       'source/scale_neon.cc',
       'source/scale_neon64.cc',
       'source/scale_win.cc',
       'source/video_common.cc',
     ],
   }
 }