V4L/DVB (10247): saa7134: convert to the new v4l2 framework.

Register v4l2_device and switch to v4l2_subdev to access the i2c modules.

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