mac80211_hwsim: Register support for HE meshpoint

Some features of 802.11ax without central organizing (AP) STA can also be
used in mesh mode. hwsim can be used to assist initial development of these
features without having access to HW.

Signed-off-by: Sven Eckelmann <seckelmann@datto.com>
Link: https://lore.kernel.org/r/20190813063657.7544-1-sven@narfation.org
Signed-off-by: Johannes Berg <johannes.berg@intel.com>