iio: imu: st_lsm6dsx: add i3c basic support for LSM6DSO and LSM6DSR

For today the st_lsm6dsx driver support LSM6DSO and LSM6DSR sensor only in
spi and i2c mode.

The LSM6DSO and LSM6DSR are also i3c capable so let's give i3c support to
them.

Signed-off-by: Vitor Soares <vitor.soares@synopsys.com>
Acked-by: Lorenzo Bianconi <lorenzo@kernel.org>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>