[media] media: lirc_dev: use cdev_device_add() helper function

Replace calls to cdev_add() and device_add() with the cdev_device_add()
helper function.

Signed-off-by: David Härdeman <david@hardeman.nu>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>