i2c-piix4: Add support for the ATI SB600

Add support for the ATI SB600 SMBus controller.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
diff --git a/include/linux/pci_ids.h b/include/linux/pci_ids.h
index 8fb9c3e..182a96f 100644
--- a/include/linux/pci_ids.h
+++ b/include/linux/pci_ids.h
@@ -369,6 +369,7 @@
 #define PCI_DEVICE_ID_ATI_IXP400_SATA2	0x437a
 #define PCI_DEVICE_ID_ATI_IXP600_SATA	0x4380
 #define PCI_DEVICE_ID_ATI_IXP600_SRAID	0x4381
+#define PCI_DEVICE_ID_ATI_IXP600_SMBUS	0x4385
 #define PCI_DEVICE_ID_ATI_IXP600_IDE	0x438c
 
 #define PCI_VENDOR_ID_VLSI		0x1004