dt-bindings:iio:light:avago,apds9300: txt to yaml conversion.

This could have gone in trivial-devices.yaml, but there was a datasheet
link so I've given it a minimal file of it's own.
Very simple binding and so a very simple conversion.

Oleksandr's email address is bouncing so I've put myself as fallback
maintainer until someone else steps forward.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20201031184854.745828-14-jic23@kernel.org