drm: zte: support hdmi audio through spdif

It enables HDMI audio support through SPDIF interface based on generic
hdmi-audio-codec driver.  The HDMI hardware supports more audio
interfaces than SPDIF, like I2S, which may be added later.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
6 files changed