Pack inter mode speed features to their own struct

BUG=aomedia:2562

Change-Id: I342f5abf87aa7d82395a2a7bd9e1d35426a40861
diff --git a/av1/encoder/encoder.c b/av1/encoder/encoder.c
index df0c994..8a5a04f 100644
--- a/av1/encoder/encoder.c
+++ b/av1/encoder/encoder.c
@@ -5027,11 +5027,12 @@
     }
   }
 
-  if (!cpi->sf.disable_obmc && cpi->sf.prune_obmc_prob_thresh > 0 &&
+  if (!cpi->sf.inter_sf.disable_obmc &&
+      cpi->sf.inter_sf.prune_obmc_prob_thresh > 0 &&
       cm->current_frame.frame_type == KEY_FRAME) {
     av1_copy(cpi->obmc_probs, default_obmc_probs);
   }
-  if (cpi->sf.prune_warped_prob_thresh > 0 &&
+  if (cpi->sf.inter_sf.prune_warped_prob_thresh > 0 &&
       cm->current_frame.frame_type == KEY_FRAME) {
     av1_copy(cpi->warped_probs, default_warped_probs);
   }