ieee80211: Add EHT (802.11be) definitions

Based on Draft P802.11be_D1.4.
Signed-off-by: Ilan Peer <ilan.peer@intel.com>
Link: https://lore.kernel.org/r/20220214173004.928e23cacb2b.Id30a3ef2844b296efbd5486fe1da9ca36a95c5cf@changeidSigned-off-by: Johannes Berg <johannes.berg@intel.com>