Alignment of THR_MODES to vp9_mode_order[]

Change-Id: I4032dd0442043543954dcb3724df974b7cc7e515

vp9/encoder/vp9_onyx_int.h

@@ -141,13 +141,15 @@ typedef struct {
   MBGRAPH_MB_STATS *mb_stats;
 } MBGRAPH_FRAME_STATS;
 
+// This enumerator type needs to be kept aligned with the mode order in
+// const MODE_DEFINITION vp9_mode_order[MAX_MODES] used in the rd code.
 typedef enum {
-  THR_ZEROMV,
-  THR_DC,
-
   THR_NEARESTMV,
   THR_NEARMV,
 
+  THR_ZEROMV,
+  THR_DC,
+
   THR_ZEROG,
   THR_NEARESTG,