avcodec: add codec_id/type to subtitles also

modules/codec/avcodec/subtitle.c

@@ -69,6 +69,9 @@ int InitSubtitleDec(decoder_t *dec, AVCodecContext *context,
     if (!sys)
         return VLC_ENOMEM;
 
+    codec->type = CODEC_TYPE_SUBTITLE;
+    context->codec_type = CODEC_TYPE_SUBTITLE;
+    context->codec_id = codec_id;
     sys->p_context = context;
     sys->p_codec = codec;
     sys->i_codec_id = codec_id;