* Freescale Message Interrupt Module

Reguired properities:
- compatible : should be
  "fsl,<chip>-msg", "fsl,mpic-msg" for 85xx/86xx message interrupt module.
- reg : should contain message registers location and length.
- interrupts : should contain 4 interrupts for 4 message interrupt source.
- interrupt-parent: the phandle for the interrupt source. Only the mpic have
  message interrupt source.

Example:
        message@41400 {
		compatible = "fsl,p2020rdb-msg","fsl,mpic-msg";
		reg = <0x41400 0x200>;
		interrupts = <0xb0 2 0xb1 2 0xb2 2 0xb3 2>;
		interrupt-parent = < &mpic >;
	};

        message@42400 {
		compatible = "fsl,p2020rdb-msg","fsl,mpic-msg";
		reg = <0x42400 0x200>;
		interrupts = <0xb4 2 0xb5 2 0xb6 2 0xb7 2>;
		interrupt-parent = < &mpic >;
	};

The above examples shows two message interrupt modules on P2020RDB.
