wil6210: Fix driver down flow

Stations disconnection is executed as part of wil_reset so no
need to do it in wil_down.
Removal of the disconnect operation will also preserve the lock
of wil->mutex during the whole reset flow and prevent handling of
connect event while resetting.
Set wil_status_resetting in earlier stage in the flow to prevent
double resetting call in case communication with FW fails while
bringing the interface down.

Change-Id: Ifb92501aab14843309fed8e1214a867b2ccccfce
Signed-off-by: Lazar Alexei <qca_ailizaro@qca.qualcomm.com>
Signed-off-by: Maya Erez <qca_merez@qca.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>
Git-commit: b0c0e688e523eba14abf21ac246b7dd88f5574fa
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/kvalo/ath.git


CRs-Fixed: 1063261
Signed-off-by: Maya Erez <merez@codeaurora.org>