mac80211: fix kernel-doc

Moving information from config_interface to bss_info_changed
removed struct ieee80211_if_conf which the documentation still
refers to, additionally there's one kernel-doc description too
much and one other missing, fix all this.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>