Warn on 6Ghz band

[guilhem]

dawn: frequency 6135 is beyond the last known band. Using '802_11a' band parameters

[ssdnvv]

Any news here on DAWN for 6GHz band? As WIFI 6E is available and rockstable for OpenWrt (AsiaRF AW7916-NPD has been available for 3 years by now) and WIFI 7 is getting ready (e.g. on the BPI-R4 and the Turris Omnia NG), DAWN could make a difference in this setup as well. As fast as WIFI6E is, my devices keep getting clued to this band even with bad SNR, where in a 2,4/5,8GHz situation DAWN would have kicked the device already...