airo: re-arrange WPA capability checks

The capability register has to be read for other (upcoming) stuff, so fold
the WPA test function back into _init_airo_card() and move the netdevice
registration stuff above it so that the netdevice has a name by the time
the card's capabilities are printed out.

Signed-off-by: Dan Williams <dcbw@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>