can: sja1000: Add support for the new 4 channel EMS CPC-PCI cards

This patch adds support to the ems_pci driver for the new, v2,
4 channel CPC-PCI/PCIe/104P CAN cards from EMS Dr. Thomas Wuensche.

Signed-off-by: Sebastian Haas <haas@ems-wuensche.com>
Signed-off-by: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: David S. Miller <davem@davemloft.net>