mac80211: conditionally advertise HE in probe requests

While building probe requests, only enable HE capability if
there are actually any channels in the band with HE enabled,
otherwise we're not really capable. We're doing the same in
association requests, so doing it here makes it consistent.

This also makes HE not appear available if it isn't due to
regulatory constraints.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20210618133832.b5513f2af335.Ic01862678712ae4238cea43ad2185928865efad2@changeid


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