dt-bindings: iio: tsl2772: add new bindings

This patch adds the new properties amstaos,proximity-diodes and
led-max-microamp to the tsl2772 driver. This patch also removes the
driver from the trivial-devices.txt.

Signed-off-by: Brian Masney <masneyb@onstation.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>