dt-bindings:iio:proximity: Add sx9360 binding

Add binding to configure Semtech sx9360 sensor.
It is a simpler version of sx9324.

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/20220101203800.290387-3-gwendal@chromium.org


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