V4L/DVB: w9966: convert to V4L2

Note that I have not been able to find anyone with this hardware. I tried
contacting the author without success, searched on eBay and similar places
without luck either.

So this conversion is untested. That said, it was pretty straightforward
so it is time to have this driver join the V4L2 world at last.

Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>