fjes: net_device_ops.ndo_open and .ndo_stop

This patch adds net_device_ops.ndo_open and .ndo_stop
callback. These function is called when network device
activation and deactivation.

Signed-off-by: Taku Izumi <izumi.taku@jp.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>