wl1271: Change booleans in struct wl1271 into a flags bitmask

For cleaner implementation, change the bunch of booleans in the struct wl1271
structure into a flags bitmask.

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