dt-bindings: iio: addac: adi,ad74413r: improve example

Improve example by: dropping unrelated properties (status and cs-gpios)
and using generic node name.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20221004115642.63749-2-krzysztof.kozlowski@linaro.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>