* XEN frontend i2c controller

Required properties:
- compatible :
  - "xen,i2c" for xen i2c frontend
- be-adapter : the backend i2c adapter name

Examples:

xen_i2c0: xen_i2c@0 {
	compatible = "xen,i2c";
	be-adapter = "5a800000.i2c";
	status = "okay";
};