Multiple issues:
 - there are no "default" values needed
 - cw_min/cw_max can be larger than documented
 - restructure to decrease size
 - use get_unaligned_le16
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>