Fix enum order in aomdx.h for ABI compatibility

The ABI change was wrongly introduced in the
following commit
c8d7b28163e Add control calls in decoder

Change-Id: I770901a6570bc9670fbbe355351ed1745d8f9f6f
diff --git a/aom/aomdx.h b/aom/aomdx.h
index 01b40d0..399c669 100644
--- a/aom/aomdx.h
+++ b/aom/aomdx.h
@@ -375,14 +375,14 @@
    */
   AOMD_GET_FWD_KF_PRESENT,
 
-  /*!\brief Codec control function to check the presence of altref frames */
-  AOMD_GET_ALTREF_PRESENT,
-
   /*!\brief Codec control function to get the frame flags of the previous frame
    * decoded. This will return a flag of type aom_codec_frame_flags_t.
    */
   AOMD_GET_FRAME_FLAGS,
 
+  /*!\brief Codec control function to check the presence of altref frames */
+  AOMD_GET_ALTREF_PRESENT,
+
   /*!\brief Codec control function to get tile information of the previous frame
    * decoded. This will return a struct of type aom_tile_info.
    */