findvhtchan
c = findvhtchan(ic, chan, IEEE80211_CHAN_VHT160);
c = findvhtchan(ic, chan, IEEE80211_CHAN_VHT80P80);
c = findvhtchan(ic, chan, IEEE80211_CHAN_VHT80);
c = findvhtchan(ic, chan, IEEE80211_CHAN_VHT40U);
c = findvhtchan(ic, chan, IEEE80211_CHAN_VHT40D);
c = findvhtchan(ic, chan, IEEE80211_CHAN_VHT20);