cfg80211: allow per interface TX power setting

The TX power setting is currently per wiphy (hardware
device) but with multi-channel capabilities that doesn't
make much sense any more.

Allow drivers (and mac80211) to advertise support for
per-interface TX power configuration. When the TX power
is configured for the wiphy, the wdev will be NULL and
the driver can still handle that, but when a wdev is
given the TX power can be set only for that wdev now.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/drivers/net/wireless/rndis_wlan.c b/drivers/net/wireless/rndis_wlan.c
index bd1f0cb..5390af3 100644
--- a/drivers/net/wireless/rndis_wlan.c
+++ b/drivers/net/wireless/rndis_wlan.c
@@ -490,9 +490,12 @@
 static int rndis_set_wiphy_params(struct wiphy *wiphy, u32 changed);
 
 static int rndis_set_tx_power(struct wiphy *wiphy,
+			      struct wireless_dev *wdev,
 			      enum nl80211_tx_power_setting type,
 			      int mbm);
-static int rndis_get_tx_power(struct wiphy *wiphy, int *dbm);
+static int rndis_get_tx_power(struct wiphy *wiphy,
+			      struct wireless_dev *wdev,
+			      int *dbm);
 
 static int rndis_connect(struct wiphy *wiphy, struct net_device *dev,
 				struct cfg80211_connect_params *sme);
@@ -1903,6 +1906,7 @@
 }
 
 static int rndis_set_tx_power(struct wiphy *wiphy,
+			      struct wireless_dev *wdev,
 			      enum nl80211_tx_power_setting type,
 			      int mbm)
 {
@@ -1930,7 +1934,9 @@
 	return -ENOTSUPP;
 }
 
-static int rndis_get_tx_power(struct wiphy *wiphy, int *dbm)
+static int rndis_get_tx_power(struct wiphy *wiphy,
+			      struct wireless_dev *wdev,
+			      int *dbm)
 {
 	struct rndis_wlan_private *priv = wiphy_priv(wiphy);
 	struct usbnet *usbdev = priv->usbdev;