iio: bmi160: Fix output data rate for accel

Format is INT_PLUS_MICRO and micro odr part of ODR should
be parts of a micro.

Also s/8000/800 this is obviously a typo.

Fixes: 77c4ad2d ("iio: imu: Add initial support for Bosch BMI160")
Signed-off-by: Daniel Baluta <daniel.baluta@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>