Modifies inter/intra coding to allow all tx types

The nominal tx_type for a given mode is used as a context
to encode the actual tx_type for intra.

Results:
derflr: -0.241% BDRATE
hevcmr: -0.366% BDRATE

Change-Id: Icfe7b0a58d79bc6497a06e3441779afec6e01e21

vp10/encoder/subexp.c

@@ -212,3 +212,12 @@ void vp10_cond_prob_diff_update(vpx_writer *w, vpx_prob *oldp,
     vpx_write(w, 0, upd);
   }
 }
+
+int vp10_cond_prob_diff_update_savings(vpx_prob *oldp,
+                                       const unsigned int ct[2]) {
+  const vpx_prob upd = DIFF_UPDATE_PROB;
+  vpx_prob newp = get_binary_prob(ct[0], ct[1]);
+  const int savings = vp10_prob_diff_update_savings_search(ct, *oldp, &newp,
+                                                           upd);
+  return savings;
+}