driver: sensor: Add vl53l0x

Add driver for ST vl53l0x time of flight sensor.
This driver can be used in 2 modes :
  * proximity sensor :
      configure VL53L0X_PROXIMITY_THRESHOLD
      will return 1 if target is between sensor and threshold,
      else, 0
  * distance sensor :
      will return the distance in millimeters from sensor to target

This driver use the official STMicroelectronics library for vl53l0x.
(in ext/hal/st/lib/sensor/vl53l0x)

Signed-off-by: Vincent Veron <vincent.veron@st.com>