drivers: adxl367: add support

Add driver support for adxl367 accelerometer.

The ADXL367 is an ultralow power, 3-axis microelectromechanical
systems (MEMS) accelerometer that consumes only 0.89 μA at
a 100 Hz output data rate and 180 nA when in motion-triggered
wake-up mode. Unlike accelerometers that use power duty cycling
to achieve low power consumption, the ADXL367 does not alias
input signals by undersampling, but samples the full bandwidth of
the sensor at all data rates.

Signed-off-by: Antoniu Miclaus <antoniu.miclaus@analog.com>