[POWERPC] Fix ethernet PHY support on MPC8544 DS

The MPC8544 dts needed to set the new phy-connection-type to rgmii-id
for the Vitesse PHY on the board to work properly.
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>

arch/powerpc/boot/dts/mpc8544ds.dts

@@ -104,6 +104,7 @@
 			interrupts = <1d 2 1e 2 22 2>;
 			interrupt-parent = <&mpic>;
 			phy-handle = <&phy0>;
+			phy-connection-type = "rgmii-id";
 		};
 
 		ethernet@26000 {
@@ -117,6 +118,7 @@
 			interrupts = <1f 2 20 2 21 2>;
 			interrupt-parent = <&mpic>;
 			phy-handle = <&phy1>;
+			phy-connection-type = "rgmii-id";
 		};
 
 		serial@4500 {