Annapurna Labs MSIX handler

Properties:
- compatible : Should contain "annapurna-labs,al-msix".
- reg : Offset and length of the MSIX address space
- interrupts : first and last irq to be configured as edge triggered, as
               required for MSIX

Example:

msix {
	compatible = "annapurna-labs,al-msix";
	reg = <0xfbe00000 0x100000>;
	interrupts = <0 96 1 0 159 1>;
};
