iio: magnetometer: yas530: Add IIO scaling to "chip_info"

Add IIO scaling to the "chip_info" structure to ease the handling to
different YAS variants.

Signed-off-by: Jakob Hauser <jahau@rocketmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/a12f892633bbee13a8856c231dc793ebbc5d3a03.1660337264.git.jahau@rocketmail.com


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