* Rockchip Ion driver

Required properties:
- compatible: Should be "rockchip,ion"

Optional properties:
- cma-heap: Allocate continous physicall region.
  Should define reg with two u32 values:
    - reg0: base address of cma region
    - reg1: size of cma region
- system-heap: Allocate continous virtual region

Examples:
	ion {
		compatible = "rockchip,ion";
		#address-cells = <1>;
		#size-cells = <0>;

		cma-heap {
			reg = <0x00000000 0x02000000>;
		};

		system-heap {
		};
	};