Check the entire collocated block for zeromv context

Check through all the collcated blocks in the previous frame for
zeromv mode context.

Change-Id: I1a521d49573d3def125e1a09f22b8a34c661cebf

av1/common/mvref_common.c

@@ -345,6 +345,10 @@ static void setup_ref_mv_list(const AV1_COMMON *cm, const MACROBLOCKD *xd,
 
         for (ref = 0; ref < 2; ++ref) {
           if (prev_frame_mvs->ref_frame[ref] == ref_frame) {
+            if (abs(prev_frame_mvs->mv[ref].as_mv.row) >= 16 ||
+                abs(prev_frame_mvs->mv[ref].as_mv.col) >= 16)
+              mode_context[ref_frame] |= (1 << ZEROMV_OFFSET);
+
             for (idx = 0; idx < *refmv_count; ++idx)
               if (prev_frame_mvs->mv[ref].as_int ==
                   ref_mv_stack[idx].this_mv.as_int)
@@ -358,10 +362,6 @@ static void setup_ref_mv_list(const AV1_COMMON *cm, const MACROBLOCKD *xd,
               ref_mv_stack[idx].this_mv.as_int = prev_frame_mvs->mv[ref].as_int;
               ref_mv_stack[idx].weight = 2;
               ++(*refmv_count);
-
-              if (abs(ref_mv_stack[idx].this_mv.as_mv.row) >= 8 ||
-                  abs(ref_mv_stack[idx].this_mv.as_mv.col) >= 8)
-                mode_context[ref_frame] |= (1 << ZEROMV_OFFSET);
             }
 
             ++coll_blk_count;