cfg80211: remove enum ieee80211_band

This enum is already perfectly aliased to enum nl80211_band, and
the only reason for it is that we get IEEE80211_NUM_BANDS out of
it. There's no really good reason to not declare the number of
bands in nl80211 though, so do that and remove the cfg80211 one.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/drivers/net/wireless/ath/ath9k/main.c b/drivers/net/wireless/ath/ath9k/main.c
index 50ec4c9..8b63988 100644
--- a/drivers/net/wireless/ath/ath9k/main.c
+++ b/drivers/net/wireless/ath/ath9k/main.c
@@ -1933,14 +1933,14 @@
 	if (idx == 0)
 		ath_update_survey_stats(sc);
 
-	sband = hw->wiphy->bands[IEEE80211_BAND_2GHZ];
+	sband = hw->wiphy->bands[NL80211_BAND_2GHZ];
 	if (sband && idx >= sband->n_channels) {
 		idx -= sband->n_channels;
 		sband = NULL;
 	}
 
 	if (!sband)
-		sband = hw->wiphy->bands[IEEE80211_BAND_5GHZ];
+		sband = hw->wiphy->bands[NL80211_BAND_5GHZ];
 
 	if (!sband || idx >= sband->n_channels) {
 		spin_unlock_bh(&common->cc_lock);