dt-bindings: iio: chemical: Document senseair,sunrise CO2 sensor

Add documentation for the Senseair Sunrise 006-0-0007 CO2 NDIR sensor.

Signed-off-by: Jacopo Mondi <jacopo@jmondi.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20210920135413.140310-2-jacopo+renesas@jmondi.org


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