ASoC: dt-bindings: Extend name-prefix.yaml into common DAI properties

Rename name-prefix.yaml into common DAI schema and document
'#sound-dai-cells' for completeness.  The '#sound-dai-cells' cannot be
really constrained, as there are users with value of 0, 1 and 2, but at
least it brings definition to one common place.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20221203160442.69594-1-krzysztof.kozlowski@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>