ASoC: audio-graph-card2: Purge absent supplies for device tree nodes

ASoC: audio-graph-card2: Purge absent supplies for device tree nodes

The audio graph card doesn't mark its subnodes such as multi {}, dpcm {}
and c2c {} as not requiring any suppliers. This causes a hang as Linux
waits for these phantom suppliers to show up on boot.
Make it clear these nodes have no suppliers.

Example error message:
[   15.208558] platform 2034000.i2s: deferred probe pending: platform: wait for supplier /sound/multi
[   15.208584] platform sound: deferred probe pending: asoc-audio-graph-card2: parse error

Signed-off-by: John Watts <contact@jookia.org>
Acked-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Link: https://patch.msgid.link/20241108-graph_dt_fix-v1-1-173e2f9603d6@jookia.org
Signed-off-by: Mark Brown <broonie@kernel.org>