rfkill: Register LED triggers before registering switch

Registering the switch triggers a LED event, so we must register
LED triggers before the switch.
This has a potential to fix a crash, depending on how the device
driver initializes the rfkill data structure.

Signed-off-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>