Mediatek-based GNSS Receiver DT binding

Mediatek chipsets are used in GNSS-receiver modules produced by several
vendors and can use a UART interface.

Please see Documentation/devicetree/bindings/gnss/gnss.txt for generic
properties.

Required properties:

- compatible	: Must be

			"globaltop,pa6h"

- vcc-supply	: Main voltage regulator (pin name: VCC)

Optional properties:

- current-speed		: Default UART baud rate
- gnss-fix-gpios	: GPIO used to determine device position fix state
			  (pin name: FIX, 3D_FIX)
- reset-gpios		: GPIO used to reset the device (pin name: RESET, NRESET)
- timepulse-gpios	: Time pulse GPIO (pin name: PPS1, 1PPS)
- vbackup-supply	: Backup voltage regulator (pin name: VBAT, VBACKUP)

Example:

serial@1234 {
	compatible = "ns16550a";

	gnss {
		compatible = "globaltop,pa6h";
		vcc-supply = <&vcc_3v3>;
	};
};
