wl1271: updated general parameters structure for newer firmwares

In revision 6.1.0.0.288 the general parameters structure has changed.  This
patch updates the driver code accordingly.

Signed-off-by: Luciano Coelho <luciano.coelho@nokia.com>
Reviewed-by: Juuso Oikarinen <juuso.oikarinen@nokia.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>