Turn on simple_motion_search_split on lowres

The previous commit accidentally turn it off on speed 1-2.

Change-Id: I79eba44b5e26b0e86719f12023b568c15869c717

av1/encoder/speed_features.c

diff --git a/av1/encoder/speed_features.c b/av1/encoder/speed_features.c
index ef312f6..062a605 100644
--- a/av1/encoder/speed_features.c
+++ b/av1/encoder/speed_features.c
@@ -133,6 +133,8 @@
       sf->simple_motion_search_split = 2;
     } else {
       sf->use_square_partition_only_threshold = BLOCK_32X32;
+
+      sf->simple_motion_search_split = 1;
     }
 
     if (!is_720p_or_larger) {