V4L/DVB (4053): KWorld HardwareMpegTV XPert: enable s-video/composite video inputs

- Enabled s-video and composite video inputs.
- Updated comments to reflect the current support for this card.

Signed-off-by: Michael Krufky <mkrufky@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>