BACKPORT: cfg80211: require HE capabilities for 6 GHz band

On 6 GHz band, HE capabilities must be available for all of
the interface types, otherwise we shouldn't use 6 GHz. Check
this.

Bug: 163110886

Link: https://lore.kernel.org/r/20200528213443.5881cb3c8c4a.I583b54172f91f98d44af64a16c5826fe458cbb27@changeid


Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Change-Id: I6091b10c85d34eb7ec8324a8e6d5ea3e1efecedc
(cherry picked from commit f438136528482f98535889c9a6f99bbacdd92870)
Signed-off-by: Vamsi Krishna <vamsin@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>