dt-bindings: pinctrl: mt65xx: Allow gpio-line-names

Current, the DT bindings for MediaTek's MT65xx Pin controller is missing
the gpio-line-names property, add it to the associated schema.

Signed-off-by: Ariel D'Alessandro <ariel.dalessandro@collabora.com>
Acked-by: Rob Herring (Arm) <robh@kernel.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>

Author: adalessandro

Documentation/devicetree/bindings/pinctrl/mediatek,mt65xx-pinctrl.yaml

@@ -43,6 +43,8 @@ properties:
       the amount of cells must be specified as 2. See the below mentioned gpio
       binding representation for description of particular cells.
 
+  gpio-line-names: true
+
   mediatek,pctl-regmap:
     $ref: /schemas/types.yaml#/definitions/phandle-array
     items: