TI-NSPIRE interrupt controller

Required properties:
- compatible: Compatible property value should be "lsi,zevio-intc".

- reg: Physical base address of the controller and length of memory mapped
	region.

- interrupt-controller : Identifies the node as an interrupt controller

Example:

interrupt-controller {
	compatible = "lsi,zevio-intc";
	interrupt-controller;
	reg = <0xDC000000 0x1000>;
	#interrupt-cells = <1>;
};
