Expand av1_encode_block_intra in block_rd_txfm

This will make the code a bit complicated, but it will facilitate
lv_map experiment

Change-Id: Ic2d4d2caac4d138aacc8a9e86e2f1b029395f1fc
diff --git a/av1/encoder/encodemb.h b/av1/encoder/encodemb.h
index c0967d5..46bcaad 100644
--- a/av1/encoder/encodemb.h
+++ b/av1/encoder/encodemb.h
@@ -56,6 +56,9 @@
 int av1_optimize_b(const AV1_COMMON *cm, MACROBLOCK *mb, int plane, int block,
                    TX_SIZE tx_size, int ctx);
 
+void av1_subtract_txb(MACROBLOCK *x, int plane, BLOCK_SIZE plane_bsize,
+                      int blk_col, int blk_row, TX_SIZE tx_size);
+
 void av1_subtract_plane(MACROBLOCK *x, BLOCK_SIZE bsize, int plane);
 
 void av1_set_txb_context(MACROBLOCK *x, int plane, int block, TX_SIZE tx_size,