Update libvpx snapshot to v0.9.7-p1 (Cayuga).

source/libvpx/vp8/encoder/x86/variance_ssse3.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 "vp8/encoder/variance.h"
 #include "vp8/common/pragmas.h"
 #include "vpx_ports/mem.h"
 
 extern unsigned int vp8_get16x16var_sse2
 (
     const unsigned char *src_ptr,
     int source_stride,
     const unsigned char *ref_ptr,
     int recon_stride,
@@ skipping 134 matching lines @@
         vp8_filter_block2d_bil_var_ssse3(
             src_ptr, src_pixels_per_line,
             dst_ptr, dst_pixels_per_line, 8,
             xoffset, yoffset,
             &xsum0, &xxsum0);
     }
 
     *sse = xxsum0;
     return (xxsum0 - ((xsum0 * xsum0) >> 7));
 }