regulator: fan53555: Explicitly include bits header

Since commit f2a9eb97 ("regulator: fan53555: Add support for
FAN53526") the driver makes use of the BIT() macro, but relies on the
bits header being implicitly included.

Explicitly pull the header in to avoid potential build failures in some
configurations.

While here, reorder include directives alphabetically.

Fixes: f2a9eb97 ("regulator: fan53555: Add support for FAN53526")
Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>
Link: https://lore.kernel.org/r/20230406171806.948290-3-cristian.ciocaltea@collabora.com


Signed-off-by: Mark Brown <broonie@kernel.org>