qcacmn: Clean up wmi.h in target_if_scan.c

Add WMI unified APIs to extract PNO related WMI events in order to
remove wmi.h inclusion in target_if_scan.c.

Change-Id: I7fd28f175de002b48c294783f69b819ce2f3e37a
CRs-fixed: 2519032
5 files changed