iio: imu: inv_icm42600: fix odr switch to the same value

iio: imu: inv_icm42600: fix odr switch to the same value

ODR switch is done in 2 steps when FIFO is on : change the ODR register
value and acknowledge change when reading the FIFO ODR change flag.
When we are switching to the same odr value, we end up waiting for a
FIFO ODR flag that is never happening.

Fix the issue by doing nothing and exiting properly when we are
switching to the same ODR value.

Fixes: ec74ae9fd37c ("iio: imu: inv_icm42600: add accurate timestamping")
Signed-off-by: Jean-Baptiste Maneyrol <jean-baptiste.maneyrol@tdk.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>