usb: host: add DT bindings for faraday fotg2

Faraday FOTG Host controller

This OTG-capable USB host controller is found in Cortina Systems

Gemini and other SoC products.

Required properties:

- compatible: should be one of:

  "faraday,fotg210"

  "cortina,gemini-usb", "faraday,fotg210"

- reg: should contain one register range i.e. start and length

- interrupts: description of the interrupt line

Optional properties:

- clocks: should contain the IP block clock

- clock-names: should be "PCLK" for the IP block clock

Required properties for "cortina,gemini-usb" compatible:

- syscon: a phandle to the system controller to access PHY registers

Optional properties for "cortina,gemini-usb" compatible:

- cortina,gemini-mini-b: boolean property that indicates that a Mini-B

  OTG connector is in use

- wakeup-source: see power/wakeup-source.txt

Example for Gemini:

usb@68000000 {

	compatible = "cortina,gemini-usb", "faraday,fotg210";

	reg = <0x68000000 0x1000>;

	interrupts = <10 IRQ_TYPE_LEVEL_HIGH>;

	clocks = <&cc 12>;

	clock-names = "PCLK";

	syscon = <&syscon>;

	wakeup-source;

};