iio: accel: adxl345: introduce interrupt handling

Add the possibility to claim an interrupt. Init the state structure
with an interrupt line obtained from the DT. The adxl345 can use
two different interrupt lines for event handling. Only one is used.

Signed-off-by: Lothar Rubusch <l.rubusch@gmail.com>
Link: https://patch.msgid.link/20241228232949.72487-2-l.rubusch@gmail.com


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