libvpx: Pull from upstream

source/libvpx/vp9/encoder/x86/vp9_variance_mmx.c

 /*
  *  Copyright (c) 2010 The WebM 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.
  */
 
 #include "./vpx_config.h"
 #include "vp9/encoder/vp9_variance.h"
 #include "vp9/common/vp9_pragmas.h"
 #include "vpx_ports/mem.h"
 
-extern unsigned int vp9_get_mb_ss_mmx(const int16_t *src_ptr);
 extern unsigned int vp9_get8x8var_mmx
 (
   const unsigned char *src_ptr,
   int  source_stride,
   const unsigned char *ref_ptr,
   int  recon_stride,
   unsigned int *SSE,
   int *Sum
 );
 extern unsigned int vp9_get4x4var_mmx
@@ skipping 118 matching lines @@
                     &sum0);
   vp9_get8x8var_mmx(src_ptr + 8 * source_stride, source_stride,
                     ref_ptr + 8 * recon_stride, recon_stride, &sse1, &sum1);
 
   var = sse0 + sse1;
   avg = sum0 + sum1;
   *sse = var;
 
   return (var - (((unsigned int)avg * avg) >> 7));
 }