cfg80211: move reg_work and reg_todo above

These will be used earlier in the next few patches.

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Tested-by: Mark Mentovai <mark@moxienet.com>
Tested-by: Bruno Randolf <br1@einfach.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>