net: dsa: Rename and export dev_to_net_device()

In preparation for using this function in net/dsa/dsa2.c, rename the function
to make its scope DSA specific, and export it.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/dsa/dsa.c b/net/dsa/dsa.c
index 22e44f6..b6d4f6a 100644
--- a/net/dsa/dsa.c
+++ b/net/dsa/dsa.c
@@ -492,7 +492,7 @@ struct mii_bus *dsa_host_dev_to_mii_bus(struct device *dev)
 }
 EXPORT_SYMBOL_GPL(dsa_host_dev_to_mii_bus);
 
-static struct net_device *dev_to_net_device(struct device *dev)
+struct net_device *dsa_dev_to_net_device(struct device *dev)
 {
 	struct device *d;
 
@@ -509,6 +509,7 @@ static struct net_device *dev_to_net_device(struct device *dev)
 
 	return NULL;
 }
+EXPORT_SYMBOL_GPL(dsa_dev_to_net_device);
 
 #ifdef CONFIG_OF
 static int dsa_of_setup_routing_table(struct dsa_platform_data *pd,
@@ -817,7 +818,7 @@ static int dsa_probe(struct platform_device *pdev)
 		dev = pd->of_netdev;
 		dev_hold(dev);
 	} else {
-		dev = dev_to_net_device(pd->netdev);
+		dev = dsa_dev_to_net_device(pd->netdev);
 	}
 	if (dev == NULL) {
 		ret = -EPROBE_DEFER;