Extend IntraBC to 4x4

Change-Id: I3f30c35bcd1bc623ad0c34c4b954ff71b2fcfd00
diff --git a/av1/decoder/decodemv.c b/av1/decoder/decodemv.c
index 3748083..e06e016 100644
--- a/av1/decoder/decodemv.c
+++ b/av1/decoder/decodemv.c
@@ -1163,7 +1163,7 @@
   mbmi->ref_frame[1] = NONE_FRAME;
 
 #if CONFIG_INTRABC
-  if (bsize >= BLOCK_8X8 && cm->allow_screen_content_tools) {
+  if (av1_allow_intrabc(bsize, cm)) {
     mbmi->use_intrabc = aom_read_symbol(r, ec_ctx->intrabc_cdf, 2, ACCT_STR);
     if (mbmi->use_intrabc) {
       mbmi->tx_size = read_tx_size(cm, xd, 1, !mbmi->skip, r);