Device tree bindings for Goodix GT9xx series touchscreen controller

Required properties:

 - compatible		: Should be "goodix,gt911"
				 or "goodix,gt9110"
				 or "goodix,gt912"
				 or "goodix,gt927"
				 or "goodix,gt9271"
				 or "goodix,gt928"
				 or "goodix,gt967"
 - reg			: I2C address of the chip. Should be 0x5d or 0x14
 - interrupt-parent	: Interrupt controller to which the chip is connected
 - interrupts		: Interrupt to which the chip is connected

Optional properties:

 - irq-gpios		: GPIO pin used for IRQ. The driver uses the
			  interrupt gpio pin as output to reset the device.
 - reset-gpios		: GPIO pin used for reset

 - touchscreen-inverted-x  : X axis is inverted (boolean)
 - touchscreen-inverted-y  : Y axis is inverted (boolean)
 - touchscreen-swapped-x-y : X and Y axis are swapped (boolean)
                             (swapping is done after inverting the axis)

Example:

	i2c@00000000 {
		/* ... */

		gt928@5d {
			compatible = "goodix,gt928";
			reg = <0x5d>;
			interrupt-parent = <&gpio>;
			interrupts = <0 0>;

			irq-gpios = <&gpio1 0 0>;
			reset-gpios = <&gpio1 1 0>;
		};

		/* ... */
	};