regulator: core: Ignore unset max_uA constraints in current limit check

We should only consider max_uA constraints if they are explicitly defined.
In cases where it is not set, we should assume the regulator has no current
limit.

Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
Link: https://patch.msgid.link/20241121-feature_poe_port_prio-v3-2-83299fa6967c@bootlin.com


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