wireless: fix 80211 kernel-doc warnings

Fix many of each of these warnings:

Warning(include/net/cfg80211.h:519): No description found for parameter 'rxrate'
Warning(include/net/mac80211.h:1163): bad line:

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>