Add plane to tx_type read/write/update functions

This is for lv_map experiment

Change-Id: Ie000f7850efac32ffb46b9a4679cff2814c6246a
diff --git a/av1/decoder/decodemv.c b/av1/decoder/decodemv.c
index 3018b79..f22f744 100644
--- a/av1/decoder/decodemv.c
+++ b/av1/decoder/decodemv.c
@@ -744,7 +744,7 @@
                       int supertx_enabled,
 #endif
 #if CONFIG_LV_MAP
-                      int block,
+                      int block, int plane,
 #endif
                       aom_reader *r) {
   MB_MODE_INFO *mbmi = &xd->mi[0]->mbmi;
@@ -763,6 +763,8 @@
 #if !CONFIG_LV_MAP
   TX_TYPE *tx_type = &mbmi->tx_type;
 #else
+  // only y plane's tx_type is transmitted
+  if (plane > 0) return;
   TX_TYPE *tx_type = &mbmi->txk_type[block];
 #endif