cfg80211: Add an attribute to set inactivity timeout in AP mode

This patch adds an attribute, NL80211_ATTR_INACTIVITY_TIMEOUT,
to set the inactivity timeout which can be used to remove the
station in AP mode. This can be passed in NL80211_CMD_START_AP
and used by the drivers which have AP MLME in firmware but
don't support get_station() properly. To disable inactivity
timer in userspace, wpa_s for example, there is a new flag,
NL80211_FEATURE_INACTIVITY_TIMER, in nl80211_feature_flags
through which drivers can register their capability to use
the inactivity timeout to free the stations.

Signed-off-by: Vasanthakumar Thiagarajan <vthiagar@qca.qualcomm.com>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index d640a39..8048058 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -413,6 +413,7 @@
  * @crypto: crypto settings
  * @privacy: the BSS uses privacy
  * @auth_type: Authentication type (algorithm)
+ * @inactivity_timeout: time in seconds to determine station's inactivity.
  */
 struct cfg80211_ap_settings {
 	struct cfg80211_beacon_data beacon;
@@ -424,6 +425,7 @@
 	struct cfg80211_crypto_settings crypto;
 	bool privacy;
 	enum nl80211_auth_type auth_type;
+	int inactivity_timeout;
 };
 
 /**