iio: imu: lsm6dsx: Move exported symbols to the IIO_LSM6DSX namespace

iio: imu: lsm6dsx: Move exported symbols to the IIO_LSM6DSX namespace

Avoid unnecessary pollution of the global symbol namespace by
moving library functions in to a specific namespace and import
that into the drivers that make use of the functions.

For more info: https://lwn.net/Articles/760045/

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20220220181522.541718-9-jic23@kernel.org
Acked-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://lore.kernel.org/r/20220604161223.461847-6-jic23@kernel.org