ipw2100: Register the wiphy device

libipw unconditionally calls wiphy_unregister, but it's up to the driver
to register it in the first place. ipw2100 fails to do so. Add the necessary
glue code, and also ensure that rfkill statuses get set up appropriately.

(Augmented for proper wiphy_unregister placement. -- JWL)

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