staging: wilc1000: use cfg80211 ssid list instead of repacking it

Avoid repacking ssid values into struct wilc_probe_ssid, and use the
cfg80211 provided struct to pass the ssid list to wilc_scan.
With this change, struct wilc_probe_ssid, struct wilc_probe_ssid_info
and function wilc_wfi_cfg_alloc_fill_ssid will not be needed anymore.

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