iio: potentiometer: mcp4531: Use i2c_get_match_data()

Replace device_get_match_data() and i2c_match_id() by i2c_get_match
_data() by making similar I2C and DT-based matching table.

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Link: https://lore.kernel.org/r/20230723102743.102284-1-biju.das.jz@bp.renesas.com


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