iio: imu: st_lsm6dsx: add support to ISM330IS

Add support to STM ISM330IS (accelerometer and gyroscope) Mems sensor.
The ISM330IS sensor can use LSM6DSO16IS as fallback device since it
implements all the ISM330IS features currently implemented in
st_lsm6dsx.

Datasheet: https://www.st.com/resource/en/datasheet/ism330is.pdf


Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://lore.kernel.org/r/4cd1614060e06f49cd92f5930d8fd40117c07920.1669279604.git.lorenzo@kernel.org


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