mac80211: Use a cfg80211_chan_def in ieee80211_hw_conf_chan

Drivers that don't use chanctxes cannot perform VHT association because
they still use a "backward compatibility" pair of {ieee80211_channel,
nl80211_channel_type} in ieee80211_conf and ieee80211_local.

Signed-off-by: Karl Beldan <karl.beldan@rivierawaves.com>
[fix kernel-doc]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/drivers/net/wireless/adm8211.c b/drivers/net/wireless/adm8211.c
index 3d339e0..f9a24e5 100644
--- a/drivers/net/wireless/adm8211.c
+++ b/drivers/net/wireless/adm8211.c
@@ -1293,7 +1293,8 @@
 {
 	struct adm8211_priv *priv = dev->priv;
 	struct ieee80211_conf *conf = &dev->conf;
-	int channel = ieee80211_frequency_to_channel(conf->channel->center_freq);
+	int channel =
+		ieee80211_frequency_to_channel(conf->chandef.chan->center_freq);
 
 	if (channel != priv->channel) {
 		priv->channel = channel;