Trade off tx size search speed feature

For speed = 4 preset, BD-rate impact is seen as -0.37%(as per AWCY run)
with encode time increment of 3.02% (averaged across multiple test cases).

STATS_CHANGED

Change-Id: I2eb9aba9308a2494aa3314c0c2f57dac4ad6f42d

av1/encoder/speed_features.c

diff --git a/av1/encoder/speed_features.c b/av1/encoder/speed_features.c
index b02e8a6..992b2f5 100644
--- a/av1/encoder/speed_features.c
+++ b/av1/encoder/speed_features.c
@@ -342,8 +342,6 @@
     sf->tx_type_search.fast_intra_tx_type_search = 1;
     sf->use_square_partition_only_threshold =
         boosted ? BLOCK_128X128 : BLOCK_4X4;
-    sf->tx_size_search_method =
-        frame_is_intra_only(cm) ? USE_FULL_RD : USE_LARGESTALL;
     sf->mv.subpel_search_method = SUBPEL_TREE_PRUNED;
     sf->adaptive_pred_interp_filter = 0;
     sf->adaptive_mode_search = 1;