Mention AVFMT_SEEK_TO_PTS in AVInputFormat flags docs

Signed-off-by: Michael Bradshaw <mbradshaw@sorensonmedia.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavformat/avformat.h

@@ -454,7 +454,7 @@ typedef struct AVInputFormat {
     /**
      * Can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_SHOW_IDS,
      * AVFMT_GENERIC_INDEX, AVFMT_TS_DISCONT, AVFMT_NOBINSEARCH,
-     * AVFMT_NOGENSEARCH, AVFMT_NO_BYTE_SEEK.
+     * AVFMT_NOGENSEARCH, AVFMT_NO_BYTE_SEEK, AVFMT_SEEK_TO_PTS.
      */
     int flags;