staging: wilc1000: wilc_set_wfi_drv_handler: pass vif index

Pass index of vif instead of hif_drv. wilc_get_vif_idx is used to get correct
index of vif.
In the handler function handle_set_wfi_drv_handler, use vif instead of hif_drv,
and use hif_drv_handler->handler instead of hif_drv when deinitialize wilc
device.

Signed-off-by: Glen Lee <glen.lee@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>