SKY81452-backlight bindings

Required properties:
- compatible		: Must be "skyworks,sky81452-backlight"

Optional properties:
- name			: Name of backlight device. Default is 'lcd-backlight'.
- gpios			: GPIO to use to EN pin.
			See Documentation/devicetree/bindings/gpio/gpio.txt
- led-sources		: List of enabled channels from 0 to 5.
			See Documentation/devicetree/bindings/leds/common.txt
- skyworks,ignore-pwm	: Ignore both PWM input
- skyworks,dpwm-mode	: Enable DPWM dimming mode, otherwise Analog dimming.
- skyworks,phase-shift	: Enable phase shift mode
- skyworks,short-detection-threshold-volt
			: It should be one of 4, 5, 6 and 7V.
- skyworks,current-limit-mA
			: It should be 2300mA or 2750mA.

Example:

	backlight {
		compatible = "skyworks,sky81452-backlight";
		name = "pwm-backlight";
		led-sources = <0 1 2 5>;
		skyworks,ignore-pwm;
		skyworks,phase-shift;
		skyworks,current-limit-mA = <2300>;
	};
