[POWERPC] mpc5200: Fix incorrect compatible string for the mdio node

The MDIO node in the lite5200b.dts file needs to also claim compatibility
with the older mpc5200 chip.  Otherwise the driver won't find the device.
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

arch/powerpc/boot/dts/lite5200b.dts

@@ -270,7 +270,7 @@
 		mdio@3000 {
 			#address-cells = <1>;
 			#size-cells = <0>;
-			compatible = "fsl,mpc5200b-mdio";
+			compatible = "fsl,mpc5200b-mdio", "fsl,mpc5200-mdio";
 			reg = <3000 400>;	// fec range, since we need to setup fec interrupts
 			interrupts = <2 5 0>;	// these are for "mii command finished", not link changes & co.
 			interrupt-parent = <&mpc5200_pic>;