wifi: cfg80211: Include operating class 137 in 6GHz band

Draft P802.11be_D3.1 added operating class to describe 320 MHz
operation in the 6GHz band. Include this new operating class in
ieee80211_operating_class_to_band().
Signed-off-by: Ilan Peer <ilan.peer@intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20230928172905.bed4a007d81b.I3eb4b8fe39c0c1a988c98a103b11a9f45a92b038@changeidSigned-off-by: Johannes Berg <johannes.berg@intel.com>

net/wireless/util.c

@@ -1999,6 +1999,7 @@ bool ieee80211_operating_class_to_band(u8 operating_class,
 		*band = NL80211_BAND_5GHZ;
 		return true;
 	case 131 ... 135:
+	case 137:
 		*band = NL80211_BAND_6GHZ;
 		return true;
 	case 81: