dt-bindings: PCI: dwc: rockchip: Use generic binding

Use the generic binding for Rockchip. This should either be
ignored/dropped or squashed into the previous commit.

Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Link: https://lore.kernel.org/r/20230731165723.53069-4-sebastian.reichel@collabora.com


Signed-off-by: Rob Herring <robh@kernel.org>