ULCB can use daughter board which is called as KingFisher.
It has extra sound interface, thus we want to use it.
But, basically, ALSA SoC can't use Multiple sound card with single
CPU sound interface (= SSI). Thus we need to use Single Sound Card
with multiple DAI interface.

To be easy to expand ULCB sound card on KingFisher, it is better to
use multi-dai-link style sound card on ULCB sound DT.

Now, "simple-audio-card" / "audio-graph-card" both can support
multi-dai-link style, but HDMI sound support (which is not yet supported
on ULCB) needs "audio-graph-card".
Using audio-graph-card is better selection.
This patch exchange current sound card to use it.
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>