wil6210: handle failure in Tx vring config

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

Change-Id: I57da43559716e7a0dccbf27260c29749256f1642
Signed-off-by: Vladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>
Git-commit: 5140a5fde2b44d366338e00ad7c2a7ede8be3e65
Git-repo: https://github.com/kvalo/ath.git


Signed-off-by: Maya Erez <merez@codeaurora.org>