The device core infrastructure is based on the presumption that
once a driver calls device_add(), it must be ready to accept
userspace interaction.

This requires splitting rc_setup_rx_device() into two functions
and reorganizing rc_register_device() so that as much work
as possible is performed before calling device_add().
Signed-off-by: NDavid Härdeman <david@hardeman.nu>
Signed-off-by: NSean Young <sean@mess.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>