dt-bindings: pinctrl: airoha: Add missing gpio-ranges property

Introduce leftover gpio-ranges property for Airoha EN7581 pinctrl binding

Fixes: d0c15cb96b74 ("dt-bindings: pinctrl: airoha: Add EN7581 pinctrl")
Signed-off-by: Lorenzo Bianconi <[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/airoha,en7581-pinctrl.yaml

···
   '#gpio-cells':
     const: 2
 
+  gpio-ranges:
+    maxItems: 1
+
   interrupt-controller: true
 
   '#interrupt-cells':