ASoC: dt-bindings: fsl_asrc: Add new property fsl, asrc-format

In order to support new EASRC and simplify the code structure,
We decide to share the common structure between them. This bring
a problem that EASRC accept format directly from devicetree, but
ASRC accept width from devicetree.

In order to align with new ESARC, we add new property fsl,asrc-format.
The fsl,asrc-format can replace the fsl,asrc-width, then driver
can accept format from devicetree, don't need to convert it to
format through width.
Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
Acked-by: Nicolin Chen <nicoleotsuka@gmail.com>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/e7acbde4b26a82b674a4091515a219e09f847eac.1587038908.git.shengjiu.wang@nxp.comSigned-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/sound/fsl,asrc.txt

@@ -51,6 +51,10 @@ Optional properties:
 			  will be in use as default. Otherwise, the big endian
 			  mode will be in use for all the device registers.
 
+   - fsl,asrc-format	: Defines a mutual sample format used by DPCM Back
+			  Ends, which can replace the fsl,asrc-width.
+			  The value is 2 (S16_LE), or 6 (S24_LE).
+
 Example:
 
 asrc: asrc@2034000 {