iio: mma8452: Use correct acceleration units.

iio: mma8452: Use correct acceleration units.

The userspace interface for acceleration sensors is documented as using
m/s^2 units [Documentation/ABI/testing/sysfs-bus-iio]

The fullscale raw value for the mma8452 (-2048) corresponds to -2G, -4G or -8G
depending on the seleted mode.

The scale table was converting to G rather than m/s^2.
Change the scaling table to match the documented interface.

Signed-off-by: Martin Fuzzey <[email protected]>
Signed-off-by: Jonathan Cameron <[email protected]>
Cc: [email protected]