Test ArgonKey board. It provides an example of how to test
all the sensors on-board. It currently enables by default
following sensors:
LPS22HB pressure/temp
HTS221 humidity
LSM6DSL accel/gyro plus LIS2MDL magn connected to it.
VL53L0x proximity
Signed-off-by: Armando Visconti <armando.visconti@st.com>