iio: accel: da280: convert probe to device-managed functions

iio: accel: da280: convert probe to device-managed functions

This is another simple conversion to device-managed functions, requiring
the use of devm_iio_device_register() and moving the disabling of the
device on a devm_add_action_or_reset() hook.

The i2c_set_clientdata() can be removed, as the PM functions can work with
just the device object, to obtain the i2c_client object.

Signed-off-by: Alexandru Ardelean <aardelean@deviqon.com>
Link: https://lore.kernel.org/r/20210628141709.80534-1-aardelean@deviqon.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>