Binding for Maxim MAX77802 32k clock generator block

This is a part of device tree bindings of MAX77802 multi-function device.
More information can be found in bindings/mfd/max77802.txt file.

The MAX77802 contains two 32.768khz clock outputs that can be controlled
(gated/ungated) over I2C.

Following properties should be present in main device node of the MFD chip.

Required properties:
- #clock-cells: From common clock binding; shall be set to 1.

Optional properties:
- clock-output-names: From common clock binding.

Each clock is assigned an identifier and client nodes can use this identifier
to specify the clock which they consume. Following indices are allowed:
     - 0: 32khz_ap clock,
     - 1: 32khz_cp clock.

Clocks are defined as preprocessor macros in dt-bindings/clock/maxim,max77802.h
header and can be used in device tree sources.

Example: Node of the MFD chip

	max77802: max77802@09 {
		compatible = "maxim,max77802";
		interrupt-parent = <&wakeup_eint>;
		interrupts = <26 0>;
		reg = <0x09>;
		#clock-cells = <1>;

		/* ... */
	};

Example: Clock consumer node

	foo@0 {
		compatible = "bar,foo";
		/* ... */
		clock-names = "my-clock";
		clocks = <&max77802 MAX77802_CLK_32K_AP>;
	};