arm64: dts: rockchip: Add RK3328 audio pipelines

The audio pipelines for HDMI and the analog codec are internal to the
SoC, so it makes sense to describe them at that level such that boards
need only enable the respective nodes for outputs they implement.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/a09c8d795e7a66fb7bc47af2b6580f6e8dbec91e.1571090991.git.robin.murphy@arm.com


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