Renesas FSI

Required properties:
- compatible			: "renesas,fsi2-<soctype>",
				  "renesas,sh_fsi2" or "renesas,sh_fsi" as
				  fallback.
				  Examples with soctypes are:
				    - "renesas,fsi2-r8a7740" (R-Mobile A1)
				    - "renesas,fsi2-sh73a0" (SH-Mobile AG5)
- reg				: Should contain the register physical address and length
- interrupts			: Should contain FSI interrupt

- fsia,spdif-connection		: FSI is connected by S/PDIF
- fsia,stream-mode-support	: FSI supports 16bit stream mode.
- fsia,use-internal-clock	: FSI uses internal clock when master mode.

- fsib,spdif-connection		: same as fsia
- fsib,stream-mode-support	: same as fsia
- fsib,use-internal-clock	: same as fsia

Example:

sh_fsi2: sh_fsi2@ec230000 {
	compatible = "renesas,sh_fsi2";
	reg = <0xec230000 0x400>;
	interrupts = <0 146 0x4>;

	fsia,spdif-connection;
	fsia,stream-mode-support;
	fsia,use-internal-clock;
};