arm64: dts: rockchip: Enable HDMI audio on Quartz64 A

This enables the i2s0 controller and the hdmi-sound node on
the PINE64 Quartz64 Model A single-board computer.

Tested-by: Peter Geis <pgwipeout@gmail.com>
Signed-off-by: Nicolas Frattaroli <frattaroli.nicolas@gmail.com>
Link: https://lore.kernel.org/r/20220611065300.885212-3-frattaroli.nicolas@gmail.com
Signed-off-by: Heiko Stuebner <heiko@sntech.de>