V4L/DVB (6203): Fix SVideo input on KWorld DVB-T 220 boards

Fix SVideo input on KWorld DVB-T 220 boards. Without this patch, the
luma pin on the SVideo input is treated as a composite in, and the
chroma pin is ignored.

Also, fix the radio, and provide a second composite input for people who
are used to the existing composite on SVideo connector behaviour.

Signed-off-by: Simon Farnsworth <simon.farnsworth@onelan.co.uk>
Reviewed-by: Hermann Pitton <hermann-pitton@arcor.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>