iio: imu: st_lsm6dsx: fix ODR check in st_lsm6dsx_write_raw

commit fc3f6ad7 upstream.

Since st_lsm6dsx i2c master controller relies on accel device as trigger
and slave devices can run at different ODRs we must select an accel_odr >=
slave_odr. Report real accel ODR in st_lsm6dsx_check_odr() in order to
properly set sensor frequency in st_lsm6dsx_write_raw and avoid to
report unsupported frequency

Fixes: 6ffb55e5 ("iio: imu: st_lsm6dsx: introduce ST_LSM6DSX_ID_EXT sensor ids")
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>