wl1271: Use NVS INI file configuration

Replace the hardcoded general and radio parameter configuration in the driver
with configuration taken from the NVS file directly. Also remove the driver
dependency to the structures with the parameter data.

Signed-off-by: Juuso Oikarinen <juuso.oikarinen@nokia.com>
Reviewed-by: Kalle Valo <kalle.valo@nokia.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>