sensor: pat9136: Add basic functionality

- Basic support with Read/Decode API for one-shot reads.
- Supported channels:
    - SENSOR_CHAN_POS_DX.
    - SENSOR_CHAN_POS_DY.
    - SENSOR_CHAN_POS_DXYZ.
    - SENSOR_CHAN_POS_DX_MM (private channel).
    - SENSOR_CHAN_POS_DY_MM (private channel).
    - SENSOR_CHAN_POS_DXYZ_MM (private channel).

Signed-off-by: Luis Ubieda <luisf@croxel.com>