arm64: dts: rockchip: add GIC ITS support to rk3588

arm64: dts: rockchip: add GIC ITS support to rk3588

Add the two Interrupt Translation Service (ITS) IPs that are part of the
GIC-600. They are mainly required for PCIe Message Signalled Interrupts
(MSI).

Co-developed-by: Kever Yang <kever.yang@rock-chips.com>
Signed-off-by: Kever Yang <kever.yang@rock-chips.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Link: https://lore.kernel.org/r/20230418142109.49762-3-sebastian.reichel@collabora.com
Signed-off-by: Heiko Stuebner <heiko@sntech.de>