arm64: dts: rockchip: rk356x: Add HDMI nodes

Add support for the HDMI port found on RK3568.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Link: https://lore.kernel.org/r/20220422072841.2206452-18-s.hauer@pengutronix.de


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