HopeRF HP03 digital pressure/temperature sensors

Required properties:
- compatible: must be "hoperf,hp03"
- xclr-gpio: must be device tree identifier of the XCLR pin.
             The XCLR pin is a reset of the ADC in the chip,
             it must be pulled HI before the conversion and
             readout of the value from the ADC registers and
             pulled LO afterward.

Example:

hp03@0x77 {
	compatible = "hoperf,hp03";
	reg = <0x77>;
	xclr-gpio = <&portc 0 0x0>;
};
