CAN: add controller hardware name for Softing cards

I just found that the controller hardware name is not set for the Softing
driver. After this patch, "$ ip -d link show" looks nicer.

Signed-off-by: Kurt Van Dijck <kurt.van.dijck@eia.be>
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>