net: tulip: make early_486_chipsets static

Fix the following sparse warning:

drivers/net/ethernet/dec/tulip/tulip_core.c:1280:28: warning: symbol
'early_486_chipsets' was not declared. Should it be static?
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/dec/tulip/tulip_core.c

@@ -1277,7 +1277,7 @@ static const struct net_device_ops tulip_netdev_ops = {
 #endif
 };
 
-const struct pci_device_id early_486_chipsets[] = {
+static const struct pci_device_id early_486_chipsets[] = {
 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82424) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_SI, PCI_DEVICE_ID_SI_496) },
 	{ },