iio: proximity: vl53l0x: Add IRQ support

VL53L0X can be configured to use interrupt pin (GPIO1)
to notify host about readiness of new measurement.

If interrupt pin is not specified, driver still uses polling.

Signed-off-by: Ivan Drobyshevskyi <drobyshevskyi@gmail.com>
Link: https://lore.kernel.org/r/20200916074458.873359-2-drobyshevskyi@gmail.com


Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>