When configuring Tx vring for new connection,
WMI call to the firmware may fail. In this case, need to
clean up properly. In particular, need to call
cfg80211_del_sta() in case of AP like interface.

Perform full "disconnect" procedure for proper clean up
Signed-off-by: Vladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>