ASoC: dt-bindings: fsl,sai: Convert format to json-schema

Convert the NXP SAI binding to DT schema format using json-schema.

The Synchronous Audio Interface (SAI) provides an interface that
supports full-duplex serial interfaces with frame synchronization
formats such as I2S, AC97, TDM, and codec/DSP interfaces.

Beside conversion, 'fsl,shared-interrupt' and '#sound-dai-cells'
are added for they are already used by some dts.

Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/1659443394-9838-1-git-send-email-shengjiu.wang@nxp.com


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