dt-bindings: PCI: dwc: Add rk3588 compatible

PCIe for RK3588 is the same as RK3568.

Signed-off-by: Lucas Tanure <lucas.tanure@collabora.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20230314135555.44162-2-lucas.tanure@collabora.com


Signed-off-by: Vinod Koul <vkoul@kernel.org>