[media] rc: ite-cir: Initialise ite_dev::rdev earlier

ite_dev::rdev is currently initialised in ite_probe() after
rc_register_device() returns.  If a newly registered device is opened
quickly enough, we may enable interrupts and try to use ite_dev::rdev
before it has been initialised.  Move it up to the earliest point we
can, right after calling rc_allocate_device().

Reported-and-tested-by: YunQiang Su <wzssyqa@gmail.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: stable@vger.kernel.org
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>