V4L/DVB (4193): Update cx2341x fw encoding API doc.

Based on recent tests it turned out that some features are not implemented.
This has now been documented.

Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
1 file changed