This automatically keeps things proper when wiphy
is renamed.

Based on patch by Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: NBen Greear <greearb@candelatech.com>
Acked-by: NBruno Randolf <br1@einfach.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>