net: Pull board_interface_eth_init() into common code

Move the board_interface_eth_init() into common ethernet uclass code,
since this function could be shared by multiple drivers.

Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Marek Vasut <marex@denx.de>
diff --git a/drivers/net/dwc_eth_qos.c b/drivers/net/dwc_eth_qos.c
index 112deb5..0cae2cf 100644
--- a/drivers/net/dwc_eth_qos.c
+++ b/drivers/net/dwc_eth_qos.c
@@ -1412,13 +1412,6 @@
 	return ret;
 }
 
-/* board-specific Ethernet Interface initializations. */
-__weak int board_interface_eth_init(struct udevice *dev,
-				    phy_interface_t interface_type)
-{
-	return 0;
-}
-
 static int eqos_probe_resources_stm32(struct udevice *dev)
 {
 	struct eqos_priv *eqos = dev_get_priv(dev);
diff --git a/net/eth-uclass.c b/net/eth-uclass.c
index b01a910..c393600 100644
--- a/net/eth-uclass.c
+++ b/net/eth-uclass.c
@@ -49,6 +49,13 @@
 /* eth_errno - This stores the most recent failure code from DM functions */
 static int eth_errno;
 
+/* board-specific Ethernet Interface initializations. */
+__weak int board_interface_eth_init(struct udevice *dev,
+				    phy_interface_t interface_type)
+{
+	return 0;
+}
+
 static struct eth_uclass_priv *eth_get_uclass_priv(void)
 {
 	struct uclass *uc;