Marvell SEI (System Error Interrupt) Controller
-----------------------------------------------

Marvell SEI (System Error Interrupt) controller is an interrupt
aggregator. It receives interrupts from several sources and aggregates
them to a single interrupt line (an SPI) on the parent interrupt
controller.

This interrupt controller can handle up to 64 SEIs, a set comes from the
AP and is wired while a second set comes from the CPs by the mean of
MSIs.

Required properties:

- compatible: should be one of:
              * "marvell,ap806-sei"
- reg: SEI registers location and length.
- interrupts: identifies the parent IRQ that will be triggered.
- #interrupt-cells: number of cells to define an SEI wired interrupt
                    coming from the AP, should be 1. The cell is the IRQ
                    number.
- interrupt-controller: identifies the node as an interrupt controller
                        for AP interrupts.
- msi-controller: identifies the node as an MSI controller for the CPs
                  interrupts.

Example:

        sei: interrupt-controller@3f0200 {
                compatible = "marvell,ap806-sei";
                reg = <0x3f0200 0x40>;
                interrupts = <GIC_SPI 0 IRQ_TYPE_LEVEL_HIGH>;
                #interrupt-cells = <1>;
                interrupt-controller;
                msi-controller;
        };