qcacmn: Move retrieval of wmi_handle to target_if layer

Remove inconsistent API for scan start and stop, where pdev_wmi_handle
is derived from psoc_handle at the WMI layer instead of using
the wmi_handle passed from the above layer i.e target_if

Change-Id: If259260e6f8cf77bf68748a8130db4440b88588a
CRs-Fixed: 2203048
5 files changed