V4L/DVB (12314): cx23885: add CAM presence checkout

Add CAM presence checkout during CiMax init for NetUP card.

CAM presence checkout is needed after power on PC.

Signed-off-by: Igor M. Liplianin <liplianin@netup.ru>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>