Cirrus Logic Madera class audio codecs gpio driver

See also the core bindings for the parent MFD driver:
See Documentation/devicetree/bindinge/mfd/madera.txt

Required properties:

  - gpio-controller : Indicates this device is a GPIO controller.
  - #gpio-cells : Must be 2. The first cell is the pin number. The second cell
    is reserved for future use and must be zero

Example:

codec: cs47l85@0 {
	compatible = "cirrus,cs47l85";

	gpio-controller;
	#gpio-cells = <2>;
};