nl80211: add kernel-doc for NL80211_FEATURE_ACTIVE_MONITOR

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

include/uapi/linux/nl80211.h

@@ -3579,6 +3579,10 @@ enum nl80211_ap_sme_features {
  *	Peering Management entity which may be implemented by registering for
  *	beacons or NL80211_CMD_NEW_PEER_CANDIDATE events. The mesh beacon is
  *	still generated by the driver.
+ * @NL80211_FEATURE_ACTIVE_MONITOR: This driver supports an active monitor
+ *	interface. An active monitor interface behaves like a normal monitor
+ *	interface, but gets added to the driver. It ensures that incoming
+ *	unicast packets directed at the configured interface address get ACKed.
  */
 enum nl80211_feature_flags {
 	NL80211_FEATURE_SK_TX_STATUS			= 1 << 0,