ipw2200: Set core hw rfkill status when hardware changes state

ipw2200 is able to detect when it's been hard-killed, but doesn't update
the core rfkill state or update userspace. Ensure that the state is updated,
allowing the rfkill core to notify userspace.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>