iio: imu: adis16480: Fix acceleration scale factor for adis16480

According to the datasheet, the range of the acceleration is [-10 g, + 10 g],
so the scale factor should be 10 instead of 5.

Signed-off-by: Dragos Bogdan <dragos.bogdan@analog.com>
Acked-by: Lars-Peter Clausen <lars@metafoo.de>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>