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
Add set/get API for max parallel active scans supported.
Max active scans allowed is set from ext service ready event
handler(8 as of now). Once FW announces this capability, FW
announce value must be used instead of hardcoded value 8.
Change-Id: I2af3a34c9f55f92c47aebbd12838a8d8fc6e3ba7
CRs-Fixed: 1095299