dts: vt8500: Fix invalid/missing cpu nodes for soc files.

vt8500, wm8650 and wm8850 have no cpu node specified.
wm8505 has a cpu node which contains an invalid compatible string, and
is missing the other required properties.

Signed-off-by: Tony Prisk <linux@prisktech.co.nz>
diff --git a/arch/arm/boot/dts/vt8500.dtsi b/arch/arm/boot/dts/vt8500.dtsi
index 4a4b96f..a0b490d 100644
--- a/arch/arm/boot/dts/vt8500.dtsi
+++ b/arch/arm/boot/dts/vt8500.dtsi
@@ -11,6 +11,16 @@
 / {
 	compatible = "via,vt8500";
 
+	cpus {
+		#address-cells = <0>;
+		#size-cells = <0>;
+
+		cpu {
+			device_type = "cpu";
+			compatible = "arm,arm926ej-s";
+		};
+	};
+
 	soc {
 		#address-cells = <1>;
 		#size-cells = <1>;