V4L/DVB: bw-qcam: convert to V4L2

Note: due to lack of hardware I was not able to test this conversion.
But it is pretty straightforward, so I do not expect any problems.

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