mjpeg: support mpo

Fixes stereoscopic_photo.mpo

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavformat/rawdec.c

@@ -206,7 +206,7 @@ AVInputFormat ff_latm_demuxer = {
 #endif
 
 #if CONFIG_MJPEG_DEMUXER
-FF_DEF_RAWVIDEO_DEMUXER(mjpeg, "raw MJPEG video", NULL, "mjpg,mjpeg", CODEC_ID_MJPEG)
+FF_DEF_RAWVIDEO_DEMUXER(mjpeg, "raw MJPEG video", NULL, "mjpg,mjpeg,mpo", CODEC_ID_MJPEG)
 #endif
 
 #if CONFIG_MLP_DEMUXER