iio: accel: bma220: convert probe to device-managed functions

This change converts the driver to use devm_iio_triggered_buffer_setup()
and devm_iio_device_register() for initializing and registering the IIO
device.

The bma220_deinit() is converted into a callback for a
devm_add_action_or_reset() hook, so that the device is put in stand-by when
the driver gets uninitialized.
The return value of the bma220_deinit() function isn't used as it does not
add any value. On the error path of the probe function, this can just
override the actual error with -EBUSY, or can even return 0 (no error), on
the error path.

Signed-off-by: Alexandru Ardelean <aardelean@deviqon.com>
Link: https://lore.kernel.org/r/20210625140137.362282-1-aardelean@deviqon.com


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