net: fec: set dev->seq to priv->dev_id

To platforms has two enet interface, using dev->seq could
avoid conflict.

i.MX6UL/ULL evk board net get the wrong MAC address from fuse,
eth1 get MAC0 address, eth0 get MAC1 address from fuse. Set the
priv->dev_id to device->seq as the real net interface alias id then
.fec_get_hwaddr() read the related MAC address from fuse.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>

drivers/net/fec_mxc.c

@@ -1251,7 +1251,6 @@ static int fecmxc_probe(struct udevice *dev)
 	struct eth_pdata *pdata = dev_get_platdata(dev);
 	struct fec_priv *priv = dev_get_priv(dev);
 	struct mii_dev *bus = NULL;
-	int dev_id = -1;
 	uint32_t start;
 	int ret;
 
@@ -1272,9 +1271,9 @@ static int fecmxc_probe(struct udevice *dev)
 	}
 
 	fec_reg_setup(priv);
-	priv->dev_id = (dev_id == -1) ? 0 : dev_id;
 
-	bus = fec_get_miibus((ulong)priv->eth, dev_id);
+	priv->dev_id = dev->seq;
+	bus = fec_get_miibus((ulong)priv->eth, dev->seq);
 	if (!bus) {
 		ret = -ENOMEM;
 		goto err_mii;