arm64: dts: rockchip: add rk3588 PCIe2 support

Add all three PCIe2 IP blocks to the RK3588 DT. Note, that RK3588
also has two PCIe3 IP blocks, that will be handled separately.

Co-developed-by: Kever Yang <kever.yang@rock-chips.com>
Signed-off-by: Kever Yang <kever.yang@rock-chips.com>
Tested-by: Jagan Teki <jagan@edgeble.ai> # edgeble-neu6a, 6b
Reviewed-by: Jagan Teki <jagan@edgeble.ai>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Link: https://lore.kernel.org/r/20230731165723.53069-6-sebastian.reichel@collabora.com


Signed-off-by: Heiko Stuebner <heiko@sntech.de>