dt-bindings: pinctrl: mediatek: mt8183: Allow gpio-line-names

Add support for the 'gpio-line-names' property in the MT8183 pinctrl
binding.
This allows naming the GPIOs, which is already done in several
device trees (e.g. mt8183-kukui-jacuzzi.dtsi, mt8183-kukui-kakadu.dtsi,
mt8183-kukui-krane.dtsi), but was previously generating DT schema
warnings.

Signed-off-by: Julien Massot <[e-mail]>
Reviewed-by: AngeloGioacchino Del Regno <[e-mail]>
Acked-by: Rob Herring (Arm) <[e-mail]>
Link: https://lore.kernel.org/[e-mail]
Signed-off-by: Linus Walleij <[e-mail]>

Documentation/devicetree/bindings/pinctrl/mediatek,mt8183-pinctrl.yaml

···
     description:
       GPIO valid number range.
 
+  gpio-line-names: true
+
   interrupt-controller: true
 
   interrupts: