iio: mma8452: leave sysfs namings to the iio core

This doesn't actually change anything since the core names the sysfs folder
for the iio event attributes "events" anyways. It only leaves the job to the
core.

Signed-off-by: Martin Kepplinger <martin.kepplinger@theobroma-systems.com>
Signed-off-by: Christoph Muellner <christoph.muellner@theobroma-systems.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>