nl80211: add PROTECTED_TWT nl80211 extended feature

Add API for telling whether the driver supports protected TWT.
The protected_twt capability in the RSNXE will be based on this.

Signed-off-by: Shaul Triebitz <shaul.triebitz@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/20200131111300.891737-23-luca@coelho.fi
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

include/uapi/linux/nl80211.h

@@ -11,7 +11,7 @@
  * Copyright 2008 Jouni Malinen <jouni.malinen@atheros.com>
  * Copyright 2008 Colin McCabe <colin@cozybit.com>
  * Copyright 2015-2017	Intel Deutschland GmbH
- * Copyright (C) 2018-2019 Intel Corporation
+ * Copyright (C) 2018-2020 Intel Corporation
  *
  * Permission to use, copy, modify, and/or distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
@@ -5652,6 +5652,8 @@ enum nl80211_feature_flags {
  *	forwarding of preauth frames over the control port. They are then
  *	handled as ordinary data frames.
  *
+ * @NL80211_EXT_FEATURE_PROTECTED_TWT: Driver supports protected TWT frames
+ *
  * @NUM_NL80211_EXT_FEATURES: number of extended features.
  * @MAX_NL80211_EXT_FEATURES: highest extended feature index.
  */
@@ -5701,6 +5703,7 @@ enum nl80211_ext_feature_index {
 	NL80211_EXT_FEATURE_AQL,
 	NL80211_EXT_FEATURE_BEACON_PROTECTION,
 	NL80211_EXT_FEATURE_CONTROL_PORT_NO_PREAUTH,
+	NL80211_EXT_FEATURE_PROTECTED_TWT,
 
 	/* add new features before the definition below */
 	NUM_NL80211_EXT_FEATURES,