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

source/libvpx/vpx/src/vpx_encoder.c

Index: source/libvpx/vpx/src/vpx_encoder.c
===================================================================
--- source/libvpx/vpx/src/vpx_encoder.c	(revision 96967)
+++ source/libvpx/vpx/src/vpx_encoder.c	(working copy)
@@ -16,6 +16,7 @@
 #include <limits.h>
 #include <string.h>
 #include "vpx/internal/vpx_codec_internal.h"
+#include "vpx_config.h"
 
 #define SAVE_STATUS(ctx,var) (ctx?(ctx->err = var):var)
 
@@ -40,6 +41,9 @@
     else if ((flags & VPX_CODEC_USE_PSNR)
              && !(iface->caps & VPX_CODEC_CAP_PSNR))
         res = VPX_CODEC_INCAPABLE;
+    else if ((flags & VPX_CODEC_USE_OUTPUT_PARTITION)
+             && !(iface->caps & VPX_CODEC_CAP_OUTPUT_PARTITION))
+        res = VPX_CODEC_INCAPABLE;
     else
     {
         ctx->iface = iface;