dt-bindings: iio: chemical: add aosong,ags02ma

Add bindings for Aosong AGS02MA TVOC sensor.

The sensor communicates over i2c with the default address 0x1a.
TVOC values can be read in the units of ppb and ug/m^3 at register 0x00.

Datasheet: https://asairsensors.com/wp-content/uploads/2021/09/AGS02MA.pdf


Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Anshul Dalal <anshulusr@gmail.com>
Link: https://lore.kernel.org/r/20231215162312.143568-2-anshulusr@gmail.com


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