arm64: dts: rockchip: add mipi dcphy nodes to rk3588

Add the two MIPI-DC-phy nodes to the RK3588, that will be used by the
DSI2 controllers and hopefully in some future also for camera input.

Signed-off-by: Heiko Stuebner <heiko.stuebner@cherry.de>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Tested-by: Sebastian Reichel <sebastian.reichel@collabora.com> # RK3588 EVB1
Link: https://lore.kernel.org/r/20250226140942.3825223-2-heiko@sntech.de


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