LinuxKPI 802.11 / rtw88: make packets flow again

In 886653492945f we added checks for packets to only go out if the
station is known to the firmware (amongst others) as there are
implications in drivers.
Unfortunately rtw88 does not support the mac80211 (*sta_state)() KPI
but only the fallback (*sta_add/remove)() in which case the station is
only added to firmware when going from AUTH to ASSOC. That means we
had no chance to get authenticated anymore.

PR: 283142, 274382
Fixes: 886653492945f (make sure we can send DISASSOC or DEAUTH frames)
Tested by: imb protected-networks.net, oleg.nauman gmail.com
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D48161

(cherry picked from commit 2372f8cc640c2f4ab82831e6ac0e27ab6c18321a)