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/atmel/atmel.c b/drivers/net/wireless/atmel/atmel.c
index 6a1f03c..8f8f37f 100644
--- a/drivers/net/wireless/atmel/atmel.c
+++ b/drivers/net/wireless/atmel/atmel.c
@@ -2434,7 +2434,7 @@
 
 			/* Values in MHz -> * 10^5 * 10 */
 			range->freq[k].m = 100000 *
-			 ieee80211_channel_to_frequency(i, IEEE80211_BAND_2GHZ);
+			 ieee80211_channel_to_frequency(i, NL80211_BAND_2GHZ);
 			range->freq[k++].e = 1;
 		}
 		range->num_frequency = k;