dt-bindings: power: supply: rt5033-battery: Apply unevaluatedProperties

Additionally to the already available ref "power-supply.yaml", replace
"additionalProperties: false" by "unevaluatedProperties: false". Otherwise,
when referencing rt5033-battery in an example, message "'power-supplies' does
not match any of the regexes: 'pinctrl-[0-9]+'" will be returned.

Signed-off-by: Jakob Hauser <jahau@rocketmail.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Acked-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Signed-off-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/ef86067348f01a3bbf1bd9b4f81716b62ea1f552.1684182964.git.jahau@rocketmail.com