arm64: dts: rockchip: Add HDMI supplies on Rock960

Add the avdd-0v9-supply and avdd-1v8-supply regulators to
hdmi node for Rock960 to silence the following dmesg warning.

[    6.582782] dwhdmi-rockchip ff940000.hdmi: supply avdd-0v9 not found, using dummy regulator
[    6.583094] dwhdmi-rockchip ff940000.hdmi: supply avdd-1v8 not found, using dummy regulator

Signed-off-by: Peter Robinson <pbrobinson@gmail.com>
Link: https://lore.kernel.org/r/20221102143242.1126229-1-pbrobinson@gmail.com


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