Broadcom BCM2835 auxiliary peripheral support

This binding uses the common clock binding:
    Documentation/devicetree/bindings/clock/clock-bindings.txt

The auxiliary peripherals (UART, SPI1, and SPI2) have a small register
area controlling clock gating to the peripherals, and providing an IRQ
status register.

Required properties:
- compatible:	Should be "brcm,bcm2835-aux"
- #clock-cells:	Should be <1>. The permitted clock-specifier values can be
		  found in include/dt-bindings/clock/bcm2835-aux.h
- reg:		Specifies base physical address and size of the registers
- clocks:	The parent clock phandle

Example:

	clocks: cprman@7e101000 {
		compatible = "brcm,bcm2835-cprman";
		#clock-cells = <1>;
		reg = <0x7e101000 0x2000>;
		clocks = <&clk_osc>;
	};

	aux: aux@0x7e215004 {
		compatible = "brcm,bcm2835-aux";
		#clock-cells = <1>;
		reg = <0x7e215000 0x8>;
		clocks = <&clocks BCM2835_CLOCK_VPU>;
	};