cfg80211: add NO-EHT flag to regulatory

This may be necessary in some cases, add a flag and propagate
it, just like the NO-HE that already exists.

Signed-off-by: Ilan Peer <ilan.peer@intel.com>
[split off from a combined 320/no-EHT patch]
Link: https://lore.kernel.org/r/20220214173004.dbb85a7b86bb.Ifc1e2daac51c1cc5f895ccfb79faf5eaec3950ec@changeid


Signed-off-by: Johannes Berg <johannes.berg@intel.com>