Remove the dct_only experiment

Change-Id: I33bb6e902e3be2847ae8101199d9cbd0e1e5c38d
diff --git a/av1/common/blockd.h b/av1/common/blockd.h
index dd4a316..3008958 100644
--- a/av1/common/blockd.h
+++ b/av1/common/blockd.h
@@ -908,7 +908,7 @@
                                           TX_SIZE tx_size) {
   const MB_MODE_INFO *const mbmi = &xd->mi[0]->mbmi;
 
-  if (CONFIG_DCT_ONLY || is_inter_block(mbmi) || plane_type != PLANE_TYPE_Y ||
+  if (is_inter_block(mbmi) || plane_type != PLANE_TYPE_Y ||
       xd->lossless[mbmi->segment_id] || tx_size >= TX_32X32)
     return DCT_DCT;