staging: wilc1000: remove argument hif_drv

In previous patch we add new argument vif which has hif_drv in it's member.
Therefore, no need to pass hif_drv in those functions. Remove argument
struct host_if_drv and use hif_drv of vif.

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