staging: wilc1000: add passive scan support

Add passive scan support to the driver by passing the scan type to the
HW and configure the HW scan time if configured by the cfg80211.

Signed-off-by: Adham Abozaeid <adham.abozaeid@microchip.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>