powerpc/86xx: Add device_type entry to soc for ppc9a

The 'device_type = "soc";' line *is* needed in the DTS for get_immrbase()
to return the correct address.
Signed-off-by: NMartyn Welch <martyn.welch@gefanuc.com>
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>

arch/powerpc/boot/dts/gef_ppc9a.dts

@@ -161,6 +161,7 @@ soc@fef00000 {
 		#address-cells = <1>;
 		#size-cells = <1>;
 		#interrupt-cells = <2>;
+		device_type = "soc";
 		compatible = "fsl,mpc8641-soc", "simple-bus";
 		ranges = <0x0 0xfef00000 0x00100000>;
 		reg = <0xfef00000 0x100000>;	// CCSRBAR 1M