dt-bindings: iio: imu: st_lsm6dsx: add asm330lhhx device bindings

Add device bindings for asm330lhhx IMU sensor.
Use lsm6dsr as fallback device for asm330lhhx since it implements all
the features currently supported by asm330lhhx.

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/2e5304b7e11085d4e701b4b591fd79cc54f01301.1649100168.git.lorenzo@kernel.org


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