fsl_pq_mdio: Revive Gianfar TBI PHY support

commit 1577ecef ("netdev: Merge UCC
and gianfar MDIO bus drivers") broke the TSEC TBI PHY support: the
driver now refuses to probe TBI MDIO buses as it doesn't know about
"fsl,gianfar-tbi" compatible entry, and thus _probe() fails with
-ENODEV status.

Fix this by adding "fsl,gianfar-tbi" to the list of known Gianfar
MDIO buses.
Signed-off-by: NAnton Vorontsov <avorontsov@ru.mvista.com>
Acked-by: NAndy Fleming <afleming@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/fsl_pq_mdio.c

@@ -321,6 +321,7 @@ static int fsl_pq_mdio_probe(struct of_device *ofdev,
 	dev_set_drvdata(&ofdev->dev, new_bus);
 
 	if (of_device_is_compatible(np, "fsl,gianfar-mdio") ||
+			of_device_is_compatible(np, "fsl,gianfar-tbi") ||
 			of_device_is_compatible(np, "gianfar")) {
 #ifdef CONFIG_GIANFAR
 		tbipa = get_gfar_tbipa(regs);