[HOSTAP]: set netdev type before registering AP interface

As detailed at https://bugs.gentoo.org/159646

 hostap with hostapd confuses
udev by presenting 2 interfaces with the same MAC address. Also, at the time
of detection, the 'type' attribute is 1, identical to other hostap interfaces.

The AP interface is supposed to have type ARPHRD_IEEE80211 (801), but this is
not set until after registration.

Setting it before register_netdev() is called allows us to avoid this
confusion. We can do this by propogating the HOSTAP_INTERFACE type through
to hostap_setup_dev().

Signed-off-by: Daniel Drake <dsd@gentoo.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>