ARM: dts: imx: Add the missing cpus node

To make it consistent with the other i.mx SoCs, let's add the cpus nodes.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
diff --git a/arch/arm/boot/dts/imx31.dtsi b/arch/arm/boot/dts/imx31.dtsi
index 8116778..c34f825 100644
--- a/arch/arm/boot/dts/imx31.dtsi
+++ b/arch/arm/boot/dts/imx31.dtsi
@@ -20,6 +20,16 @@
 		serial4 = &uart5;
 	};
 
+	cpus {
+		#address-cells = <0>;
+		#size-cells = <0>;
+
+		cpu {
+			compatible = "arm,arm1136";
+			device_type = "cpu";
+		};
+	};
+
 	avic: avic-interrupt-controller@60000000 {
 		compatible = "fsl,imx31-avic", "fsl,avic";
 		interrupt-controller;