regulator: max8997: Convert to GPIO descriptors

regulator: max8997: Convert to GPIO descriptors

This rewrites the max8997 regulator driver to fetch the dvs
regulators as descriptors. This will likely mostly come from
the device tree since there are no in-tree users of the platform
data, but supplying GPIO descriptor tables from board files is
also possible if needed.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://msgid.link/r/20240220-descriptors-regulators-v1-4-097f608694be@linaro.org
Acked-by: Lee Jones <lee@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>