avcodec/h2645_parse: Move ref_idc further up in H2645NAL

This puts it directly near the NALU type which is more natural
and furthermore reduces the size of the structure because it
can be placed in padding (on 64-bit systems).

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>

libavcodec/h2645_parse.h

@@ -51,6 +51,11 @@ typedef struct H2645NAL {
      */
     int type;
 
+    /**
+     * H.264 only, nal_ref_idc
+     */
+    int ref_idc;
+
     /**
      * HEVC only, nuh_temporal_id_plus_1 - 1
      */
@@ -64,10 +69,6 @@ typedef struct H2645NAL {
     int skipped_bytes;
     int skipped_bytes_pos_size;
     int *skipped_bytes_pos;
-    /**
-     * H.264 only, nal_ref_idc
-     */
-    int ref_idc;
 } H2645NAL;
 
 typedef struct H2645RBSP {