wl1251: remove wl1271_setup()

We don't want to have any 1271 code in wl1251.

Signed-off-by: Kalle Valo <kalle.valo@nokia.com>
Reviewed-by: Luciano Coelho <luciano.coelho@nokia.com>
Reviewed-by: Vidhya Govindan <vidhya.govindan@nokia.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>