Amazon's Annapurna Labs Fabric Interrupt Controller

Required properties:

- compatible: should be "amazon,al-fic"
- reg: physical base address and size of the registers
- interrupt-controller: identifies the node as an interrupt controller
- #interrupt-cells: must be 2.
  First cell defines the index of the interrupt within the controller.
  Second cell is used to specify the trigger type and must be one of the
  following:
    - bits[3:0] trigger type and level flags
	1 = low-to-high edge triggered
	4 = active high level-sensitive
- interrupt-parent: specifies the parent interrupt controller.
- interrupts: describes which input line in the interrupt parent, this
  fic's output is connected to. This field property depends on the parent's
  binding

Example:

amazon_fic: interrupt-controller@0xfd8a8500 {
	compatible = "amazon,al-fic";
	interrupt-controller;
	#interrupt-cells = <2>;
	reg = <0x0 0xfd8a8500 0x0 0x1000>;
	interrupt-parent = <&gic>;
	interrupts = <GIC_SPI 0x0 IRQ_TYPE_LEVEL_HIGH>;
};