ASoC: dt-bindings: Add sample format conversion

Presently "convert-channels" and "convert-rate" DT bindings are available
for channel and rate fixups respectively.

Similarly add "convert-sample-format" binding to fixup DAI sample format
as well. This is added to audio-graph-card based bindings.

Signed-off-by: Sameer Pujar <spujar@nvidia.com>
Cc: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/1659936452-2254-3-git-send-email-spujar@nvidia.com


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