* Microchip MCP41010/41050/41100/42010/42050/42100 Digital Potentiometer

Datasheet publicly available at:
http://ww1.microchip.com/downloads/en/devicedoc/11195c.pdf

The node for this driver must be a child node of a SPI controller, hence
all mandatory properties described in

        Documentation/devicetree/bindings/spi/spi-bus.txt

must be specified.

Required properties:
	- compatible:  	Must be one of the following, depending on the
			model:
			"microchip,mcp41010"
			"microchip,mcp41050"
			"microchip,mcp41100"
			"microchip,mcp42010"
			"microchip,mcp42050"
			"microchip,mcp42100"

Example:
potentiometer@0 {
	compatible = "microchip,mcp41010";
	reg = <0>;
	spi-max-frequency = <500000>;
};