dt-bindings: rockchip: grf: Add missing type to 'pcie-phy' node

'pcie-phy' is missing any type. Add 'type: object' to indicate it's a
node.
Signed-off-by: Rob Herring <robh@kernel.org>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20240401204959.1698106-1-robh@kernel.orgSigned-off-by: Heiko Stuebner <heiko@sntech.de>

Documentation/devicetree/bindings/soc/rockchip/grf.yaml

@@ -171,6 +171,7 @@ allOf:
           unevaluatedProperties: false
 
         pcie-phy:
+          type: object
           description:
             Documentation/devicetree/bindings/phy/rockchip-pcie-phy.txt