ASoC: dt-bindings: audio-graph-card2: Drop incomplete example

The example in audio-graph-card2 binding is incomplete, uses
undocumented compatibles strings, and doesn't follow typical .dts
formatting. Rather than try to fix with what would probably be a lengthy
example, just drop the example.

Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20230707221725.1071292-1-robh@kernel.org


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