wil6210: Fix protection against connections during reset

Existing code that ignores connection events during
reset flow will never take effect since it locks the
same mutex taken by the reset flow.

In addition, in case of unsolicited disconnect events ignore
those as well since device is about to get reset.

Change-Id: I132040822b8c1b3d1d92965d578ed5bee0b3d1cf
Signed-off-by: Hamad Kadmany <hkadmany@codeaurora.org>