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>