Replace hard coded 8 with MAX_MIB_SIZE

This accounts for scalable mode_info size and maximum coding block
size.

Change-Id: I82277d09100532d930e13a0a8cbfee33c99e3d64

av1/common/mvref_common.c

diff --git a/av1/common/mvref_common.c b/av1/common/mvref_common.c
index 463024c..b518ee4 100644
--- a/av1/common/mvref_common.c
+++ b/av1/common/mvref_common.c
@@ -570,7 +570,8 @@
           &xd->mi[mv_ref->col + mv_ref->row * xd->mi_stride]->mbmi;
 #if CONFIG_REF_MV
       if (candidate == NULL) continue;
-      if ((mi_row % 8) + mv_ref->row >= 8 || (mi_col % 8) + mv_ref->col >= 8)
+      if ((mi_row % MAX_MIB_SIZE) + mv_ref->row >= MAX_MIB_SIZE ||
+          (mi_col % MAX_MIB_SIZE) + mv_ref->col >= MAX_MIB_SIZE)
         continue;
 #endif
       different_ref_found = 1;
@@ -621,7 +622,8 @@
             &xd->mi[mv_ref->col + mv_ref->row * xd->mi_stride]->mbmi;
 #if CONFIG_REF_MV
         if (candidate == NULL) continue;
-        if ((mi_row % 8) + mv_ref->row >= 8 || (mi_col % 8) + mv_ref->col >= 8)
+        if ((mi_row % MAX_MIB_SIZE) + mv_ref->row >= MAX_MIB_SIZE ||
+            (mi_col % MAX_MIB_SIZE) + mv_ref->col >= MAX_MIB_SIZE)
           continue;
 #endif