cfg80211: pass a channel definition struct

Instead of passing a channel pointer and channel type
to all functions and driver methods, pass a new channel
definition struct. Right now, this struct contains just
the control channel and channel type, but for VHT this
will change.

Also, add a small inline cfg80211_get_chandef_type() so
that drivers don't need to use the _type field of the
new structure all the time, which will change.

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 5390af3..abe1d03 100644
--- a/drivers/net/wireless/rndis_wlan.c
+++ b/drivers/net/wireless/rndis_wlan.c
@@ -2293,7 +2293,7 @@
 {
 	struct rndis_wlan_private *priv = wiphy_priv(wiphy);
 	struct usbnet *usbdev = priv->usbdev;
-	struct ieee80211_channel *channel = params->channel;
+	struct ieee80211_channel *channel = params->chandef.chan;
 	struct ndis_80211_ssid ssid;
 	enum nl80211_auth_type auth_type;
 	int ret, alg, length, chan = -1;