mac80211: add missing kernel-doc

Add a few kernel-doc descriptions that were missed
during mesh development.

Reported-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Ashok Nagarajan <ashok@cozybit.com>
Acked-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/sta_info.h

@@ -271,6 +271,9 @@ struct sta_ampdu_mlme {
  * @plink_timer: peer link watch timer
  * @plink_timer_was_running: used by suspend/resume to restore timers
  * @t_offset: timing offset relative to this host
+ * @t_offset_setpoint: reference timing offset of this sta to be used when
+ * 	calculating clockdrift
+ * @ch_type: peer's channel type
  * @debugfs: debug filesystem info
  * @dead: set to true when sta is unlinked
  * @uploaded: set to true when sta is uploaded to the driver