regulator: da9062: Simplify the code iterating all regulators

It's more straightforward to use for statement here.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Steve Twiss <stwiss.opensource@diasemi.com>
Link: https://lore.kernel.org/r/20191007115009.25672-1-axel.lin@ingics.com


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