[spatial svc] Disable auto alt reference

Change-Id: I2a41c1fe08261065dd21fe631b2b5937acfbfb51
diff --git a/vpx/src/svc_encodeframe.c b/vpx/src/svc_encodeframe.c
index 4009a8a..7ee2a98 100644
--- a/vpx/src/svc_encodeframe.c
+++ b/vpx/src/svc_encodeframe.c
@@ -604,6 +604,7 @@
 
   vpx_codec_control(codec_ctx, VP9E_SET_SVC, 1);
   vpx_codec_control(codec_ctx, VP8E_SET_TOKEN_PARTITIONS, 1);
+  vpx_codec_control(codec_ctx, VP8E_SET_ENABLEAUTOALTREF, 0);
 
   return VPX_CODEC_OK;
 }