dt-bindings: Document ltrf216a light sensor bindings

Add devicetree bindings for ltrf216a ambient light sensor.

Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Shreeya Patel <shreeya.patel@collabora.com>
Link: https://lore.kernel.org/r/20220725104050.491396-2-shreeya.patel@collabora.com


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