iio: st_gyro: Correct data for LSM9DS0 gyro

The commit 41c128cb ("iio: st_gyro: Add lsm9ds0-gyro support")
assumes that gyro in LSM9DS0 is the same as others with 0xd4 WAI ID,
but datasheet tells slight different story, i.e. the first scale factor
for the chip is 245 dps, and not 250 dps.

Correct this by introducing a separate settings for LSM9DS0.

Fixes: 41c128cb ("iio: st_gyro: Add lsm9ds0-gyro support")
Depends-on: 45a4e422 ("iio: gyro: st_gyro: fix L3GD20H support")
Cc: Leonard Crestez <leonard.crestez@nxp.com>
Cc: Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>