mac80211: fix 90 kernel-doc warnings

Eliminate 90 of these warnings:

Warning(..//include/net/mac80211.h:1682): No description found for parameter 'drv_priv[0]'

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>