dt-bindings: pinctrl: mt8192: Add gpio-line-names property

Add the gpio-line-names optional property to the pinctrl-mt8192 binding
to prevent dt_binding_check warnings when it is present in the pinctrl
node in the Devicetree.
Signed-off-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>
Acked-by: Rob Herring <robh@kernel.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20220315211936.442708-5-nfraprado@collabora.comSigned-off-by: Linus Walleij <linus.walleij@linaro.org>

Documentation/devicetree/bindings/pinctrl/pinctrl-mt8192.yaml

@@ -29,6 +29,8 @@ properties:
     description: gpio valid number range.
     maxItems: 1
 
+  gpio-line-names: true
+
   reg:
     description: |
       Physical address base for gpio base registers. There are 11 GPIO