dt-bindings: iio: imu: Add inv_icm42600 documentation

Update the required documentation for the icm42631.

Signed-off-by: Jay Greco <grecojay@amazon.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Acked-by: Jean-Baptiste Maneyrol <jean-baptiste.maneyrol@tdk.com>
Link: https://lore.kernel.org/r/20221110192933.13616-3-grecojay@amazon.com


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