rtc: Enable early_term_after_none_split for speed=4

This CL enables sf early_term_after_none_split to speed=4.

          Instruction Count      BD-Rate Loss(%)
cpu-used    Reduction(%)    avg.psnr    ovr.psnr    ssim
   4          6.090          0.3585      0.3347    0.1042

STATS_CHANGED for --rt, speed=4

Change-Id: I30d846dc4920954c4e27b0f99ae0857d89e37952
diff --git a/av1/encoder/speed_features.c b/av1/encoder/speed_features.c
index 31f5974..db10243 100644
--- a/av1/encoder/speed_features.c
+++ b/av1/encoder/speed_features.c
@@ -1330,6 +1330,7 @@
   sf->part_sf.prune_ext_partition_types_search_level = 2;
   sf->part_sf.partition_search_breakout_rate_thr = 80;
   sf->part_sf.less_rectangular_check_level = 2;
+  sf->part_sf.early_term_after_none_split = 1;
 
   sf->rd_sf.tx_domain_dist_thres_level = 1;
   sf->rd_sf.tx_domain_dist_level = 1;