net/fec: fix the use of pdev->id

The pdev->id is used in several places for different purpose. All
these uses assume it's always the id of fec device which is >= 0.
However this is only true for non-DT case. When DT plays, pdev->id
is always -1, which will break these pdev->id users.

Instead of fixing all these users one by one, this patch introduces
a new member 'dev_id' to 'struct fec_enet_private' for holding the
correct fec device id, and replaces all the existing uses of pdev->id
with this dev_id.

Signed-off-by: Shawn Guo <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/net/ethernet/freescale/fec.c

···
 	struct	platform_device *pdev;
 
 	int	opened;
+	int	dev_id;
 
 	/* Phylib and MDIO interface */
 	struct	mii_bus *mii_bus;
···
 
 	/* Adjust MAC if using macaddr */
 	if (iap == macaddr)
-		 ndev->dev_addr[ETH_ALEN-1] = macaddr[ETH_ALEN-1] + fep->pdev->id;
+		 ndev->dev_addr[ETH_ALEN-1] = macaddr[ETH_ALEN-1] + fep->dev_id;
 }
 
 /* ------------------------------------------------------------------------- */
···
 	char mdio_bus_id[MII_BUS_ID_SIZE];
 	char phy_name[MII_BUS_ID_SIZE + 3];
 	int phy_id;
-	int dev_id = fep->pdev->id;
+	int dev_id = fep->dev_id;
 
 	fep->phy_dev = NULL;
 
···
 	 * mdio interface in board design, and need to be configured by
 	 * fec0 mii_bus.
 	 */
-	if ((id_entry->driver_data & FEC_QUIRK_ENET_MAC) && pdev->id > 0) {
+	if ((id_entry->driver_data & FEC_QUIRK_ENET_MAC) && fep->dev_id > 0) {
 		/* fec1 uses fec0 mii_bus */
 		fep->mii_bus = fec0_mii_bus;
 		return 0;
···
 	fep->mii_bus->read = fec_enet_mdio_read;
 	fep->mii_bus->write = fec_enet_mdio_write;
 	fep->mii_bus->reset = fec_enet_mdio_reset;
-	snprintf(fep->mii_bus->id, MII_BUS_ID_SIZE, "%x", pdev->id + 1);
+	snprintf(fep->mii_bus->id, MII_BUS_ID_SIZE, "%x", fep->dev_id + 1);
 	fep->mii_bus->priv = fep;
 	fep->mii_bus->parent = &pdev->dev;
 
···
 	int i, irq, ret = 0;
 	struct resource *r;
 	const struct of_device_id *of_id;
+	static int dev_id;
 
 	of_id = of_match_device(fec_dt_ids, &pdev->dev);
 	if (of_id)
···
 
 	fep->hwp = ioremap(r->start, resource_size(r));
 	fep->pdev = pdev;
+	fep->dev_id = dev_id++;
 
 	if (!fep->hwp) {
 		ret = -ENOMEM;