qcacmn: Clear num stats over QMI once WoW enter/exit

Num stats over QMI indicates how many stats requests are fetched
without triggering RTPM resume. If RTPM resume/suspend happens in
the middle then num stats over QMI counter should reset. Add logic
to reset num stats over QMI counter during WoW enter/exit.

Change-Id: I34fe93759bf8a7a2a6c0d4b389ad96b8e1ba4d6c
CRs-Fixed: 3110590