Binding for ArcticSand arc2c0608 LED driver

Required properties:
- compatible:		should be "arc,arc2c0608"
- reg:			slave address

Optional properties:
- default-brightness:	brightness value on boot, value from: 0-4095
- label:		The name of the backlight device
			See Documentation/devicetree/bindings/leds/common.txt
- led-sources:		List of enabled channels from 0 to 5.
			See Documentation/devicetree/bindings/leds/common.txt

- arc,led-config-0:	setting for register ILED_CONFIG_0
- arc,led-config-1:	setting for register ILED_CONFIG_1
- arc,dim-freq:		PWM mode frequence setting (bits [3:0] used)
- arc,comp-config:	setting for register CONFIG_COMP
- arc,filter-config:	setting for register FILTER_CONFIG
- arc,trim-config:	setting for register IMAXTUNE

Note: Optional properties not specified will default to values in IC EPROM

Example:

arc2c0608@30 {
	compatible = "arc,arc2c0608";
	reg = <0x30>;
	default-brightness = <500>;
	label = "lcd-backlight";
	linux,default-trigger = "backlight";
	led-sources = <0 1 2 5>;
};