ASoC: rockchip-max98090: Support usage with and without HDMI

Add one optional property "rockchip,hdmi-codec" to let user specify HDMI
device node in DTS so machine driver can find hdmi-codec device node for
HDMI codec DAI.

Use the presence of rockchip,audio-codec and rockchip,hdmi-codec to
specify the use case.

Use max98090 only : specify rockchip,audio-codec.
Use HDMI only: specify rockchip,hdmi-codec.
Use both max98090 and HDMI: specify rockchip,audio-codec and
rockchip,hdmi-codec.

Move these properties to optional because they are not needed for
HDMI-only use case.
"rockchip,audio-codec": The phandle of the MAX98090 audio codec
"rockchip,headset-codec": The phandle of Ext chip for jack detection

Signed-off-by: Cheng-Yi Chiang <cychiang@chromium.org>
Link: https://lore.kernel.org/r/20191028071930.145899-3-cychiang@chromium.org


Signed-off-by: Mark Brown <broonie@kernel.org>