ASoC: dt-bindings: fsl-sai: Add new property to configure dataline

"fsl,dataline" is added to configure the dataline of SAI.
It has 3 value for each configuration, first one means the type:
I2S(1) or PDM(2), second one is dataline mask for 'rx', third one is
dataline mask for 'tx'. for example:

fsl,dataline = <1 0xff 0xff 2 0xff 0x11>,

it means I2S type rx mask is 0xff, tx mask is 0xff, PDM type
rx mask is 0xff, tx mask is 0x11 (dataline 1 and 4 enabled).
Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
Link: https://lore.kernel.org/r/1655451877-16382-7-git-send-email-shengjiu.wang@nxp.comSigned-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/sound/fsl-sai.txt

@@ -49,6 +49,14 @@ Required properties:
 			  receive data by following their own bit clocks and
 			  frame sync clocks separately.
 
+  - fsl,dataline        : configure the dataline. it has 3 value for each configuration
+                          first one means the type: I2S(1) or PDM(2)
+                          second one is dataline mask for 'rx'
+                          third one is dataline mask for 'tx'.
+                          for example: fsl,dataline = <1 0xff 0xff 2 0xff 0x11>;
+                          it means I2S type rx mask is 0xff, tx mask is 0xff, PDM type
+                          rx mask is 0xff, tx mask is 0x11 (dataline 1 and 4 enabled).
+
 Optional properties:
 
   - big-endian		: Boolean property, required if all the SAI