mac80211_hwsim: add 6GHz channels

Advertise 6GHz channels to mac80211.

Signed-off-by: Ramon Fontes <ramonreisfontes@gmail.com>
Link: https://lore.kernel.org/r/20201227031155.81161-1-ramonreisfontes@gmail.com


[reword commit message]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>