iio: accel: adxl313: implement power-save on inactivity

iio: accel: adxl313: implement power-save on inactivity

Configure the link bit to associate activity and inactivity sensing,
allowing the sensor to reflect its internal power-saving state.
Additionally, enable the auto-sleep bit to transition the sensor into
auto-sleep mode during periods of inactivity, as outlined in the
datasheet.

Reviewed-by: Andy Shevchenko <andy@kernel.org>
Signed-off-by: Lothar Rubusch <l.rubusch@gmail.com>
Link: https://patch.msgid.link/20250702230819.19353-7-l.rubusch@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>