staging: wilc1000: pass vif to hostIFthread

We will pass vif, which is currently being used as net_device, instead of
hif_dev. This is the first step to use index of vif to pass to the driver.
Add new argument vif to all the functions that send message to hostIFthread and
set vif to msg.vif. As a result, hostIfthread will get vif.
In later patch, we will remove drv of host_if_msg and use vif instead of it.

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