OMAP ROM RNG driver binding

Secure SoCs may provide RNG via secure ROM calls like Nokia N900 does. The
implementation can depend on the SoC secure ROM used.

- compatible:
	Usage: required
	Value type: <string>
	Definition: must be "nokia,n900-rom-rng"

- clocks:
	Usage: required
	Value type: <prop-encoded-array>
	Definition: reference to the the RNG interface clock

- clock-names:
	Usage: required
	Value type: <stringlist>
	Definition: must be "ick"

Example:

	rom_rng: rng {
		compatible = "nokia,n900-rom-rng";
		clocks = <&rng_ick>;
		clock-names = "ick";
	};