net/can: use module_pci_driver

This patch converts the drivers in drivers/net/can/* to use
module_pci_driver() macro which makes the code smaller and a bit simpler.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Cc: Wolfgang Grandegger <wg@grandegger.com>
Cc: Marc Kleine-Budde <mkl@pengutronix.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: linux-can@vger.kernel.org
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>