iio: accel: fxls8962af: Use new EXPORT_NS_GPL_DEV_PM_OPS()

iio: accel: fxls8962af: Use new EXPORT_NS_GPL_DEV_PM_OPS()

Using this macro allows the compiler to remove unused
structures and callbacks if we are not building with
CONFIG_PM* without needing __maybe_unused markings.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Sean Nyekjaer <sean@geanix.com>
--
Switched to Paul Cercueil's more flexible implementation fo the macro.
Dropped Sean's Ack given new form of macro being used.

Acked-by: Sean Nyekjaer <sean@geanix.com>
Link: https://lore.kernel.org/r/20220925155719.3316280-3-jic23@kernel.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>