iio: pressure: hp03: Add Hope RF HP03 sensor support

Add support for HopeRF pressure and temperature sensor.

This device uses two fixed I2C addresses, one for storing
calibration coefficients and another for accessing the ADC.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Matt Ranostay <mranostay@gmail.com>
Cc: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>