iio: imu: inv_icm42600: fix timestamp reset

Timestamp reset is not done in the correct place. It must be done
before enabling buffer. The reason is that interrupt timestamping
is always happening when the chip is on, even if the
corresponding sensor is off. When the sensor restarts, timestamp
is wrong if you don't do a reset first.

Fixes: ec74ae9f ("iio: imu: inv_icm42600: add accurate timestamping")
Signed-off-by: Jean-Baptiste Maneyrol <jean-baptiste.maneyrol@tdk.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20230509152202.245444-1-inv.git-commit@tdk.com


Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>