nl80211/cfg80211/mac80211: fix wme docs

Add/fix some missing docs.

Signed-off-by: Eliad Peller <eliad@wizery.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/include/linux/nl80211.h b/include/linux/nl80211.h
index 8aa7bad..f173075 100644
--- a/include/linux/nl80211.h
+++ b/include/linux/nl80211.h
@@ -2541,8 +2541,10 @@
 /**
  * enum nl80211_sta_wme_attr - station WME attributes
  * @__NL80211_STA_WME_INVALID: invalid number for nested attribute
- * @NL80211_STA_WME_QUEUES: bitmap of uapsd queues.
- * @NL80211_STA_WME_MAX_SP: max service period.
+ * @NL80211_STA_WME_UAPSD_QUEUES: bitmap of uapsd queues. the format
+ *	is the same as the AC bitmap in the QoS info field.
+ * @NL80211_STA_WME_MAX_SP: max service period. the format is the same
+ *	as the MAX_SP field in the QoS info field (but already shifted down).
  * @__NL80211_STA_WME_AFTER_LAST: internal
  * @NL80211_STA_WME_MAX: highest station WME attribute
  */