media: buffer.rst: clean up timecode documentation

V4L2_BUF_FLAG_TIMECODE is not video capture specific, so drop that
part.

The 'Timecodes' section was a bit messy, so that's cleaned up.
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Reviewed-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
Reviewed-by: Alexandre Courbot <acourbot@chromium.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

Documentation/media/uapi/v4l/buffer.rst

@@ -230,8 +230,7 @@ struct v4l2_buffer
     * - struct :c:type:`v4l2_timecode`
       - ``timecode``
       -
-      - When ``type`` is ``V4L2_BUF_TYPE_VIDEO_CAPTURE`` and the
-	``V4L2_BUF_FLAG_TIMECODE`` flag is set in ``flags``, this
+      - When the ``V4L2_BUF_FLAG_TIMECODE`` flag is set in ``flags``, this
 	structure contains a frame timecode. In
 	:c:type:`V4L2_FIELD_ALTERNATE <v4l2_field>` mode the top and
 	bottom field contain the same timecode. Timecodes are intended to
@@ -714,10 +713,10 @@ enum v4l2_memory
 Timecodes
 =========
 
-The struct :c:type:`v4l2_timecode` structure is designed to hold a
-:ref:`smpte12m` or similar timecode. (struct
-struct :c:type:`timeval` timestamps are stored in struct
-:c:type:`v4l2_buffer` field ``timestamp``.)
+The :c:type:`v4l2_buffer_timecode` structure is designed to hold a
+:ref:`smpte12m` or similar timecode.
+(struct :c:type:`timeval` timestamps are stored in the struct
+:c:type:`v4l2_buffer` ``timestamp`` field.)
 
 
 .. c:type:: v4l2_timecode