mac80211: add missing kernel-doc

Fix mac80211 kernel-doc missing struct field:

Warning(linux-2.6.27-rc1-git2//net/mac80211/sta_info.h:329): No description found for parameter 'tid_seq[IEEE80211_QOS_CTL_TID_MASK + 1]'
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

net/mac80211/sta_info.h

@@ -204,6 +204,7 @@ struct sta_ampdu_mlme {
  * @tx_fragments: number of transmitted MPDUs
  * @txrate_idx: TBD
  * @last_txrate_idx: TBD
+ * @tid_seq: TBD
  * @wme_tx_queue: TBD
  * @ampdu_mlme: TBD
  * @timer_to_tid: identity mapping to ID timers