Switch driver over from wext to cfg80211 interface.

Some Notes:

- This patch moves the driver wholesale from wext to cfg80211. Wext
support is still provided through the cfg80211 provided wext
compatability layer.

- Currently only infrastructure mode is implemented. Ad hoc mode is not
yet implemented, but can be added.

- It does not support connecting to a specified bssid, instead roaming
is handled by the card itself. This matches the behaviour of the
existing driver.

- It has been tested using NetworkManager (via wpa_supplicant)
configured to use the wext compatability layer, and then again with the
native nl80211 layer.
Signed-off-by: Karl Relton <karllinuxtest.relton@ntlworld.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>