ipw2x00: fix rtnl mutex deadlock

This fix regression introduced by:

commit: ecb44335


Author: Stanislaw Gruszka <sgruszka@redhat.com>
Date:   Fri Aug 12 14:00:59 2011 +0200

    mac80211: fix suspend/resume races with unregister hw

Above commit add rtnl_lock() into wiphy_register(), what cause deadlock
when initializing ipw2x00 driver, which itself call wiphy_register()
from register_netdev() internal callback with rtnl mutex taken.

To fix move wiphy_register() outside register_netdev(). This solution
have side effect of not creating /sys/class/net/wlanX/phy80211 link,
but that's a minor issue we can live with.

Bisected-by: Witold Baryluk <baryluk@smp.if.uj.edu.pl>
Bisected-by: Michael Witten <mfwitten@gmail.com>
Tested-by: Witold Baryluk <baryluk@smp.if.uj.edu.pl>
Tested-by: Michael Witten <mfwitten@gmail.com>
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>