iio: temperature: mlx90614 Refactoring available filter attributes

Change/refactor to the new way of defining available attribute values.

Signed-off-by: Crt Mori <cmo@melexis.com>
Link: https://lore.kernel.org/r/20220906112632.244453-1-cmo@melexis.com


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