ASoC: dt-bindings: fsl-sai: Fix mx6ul and mx7d compatible strings

Describe existing used combinations of compatible strings on MX6UL
and MX7D, which are backward compatible with MX6SX. Add the missing
imx7d-sai compatible string which is used on i.MX7 .

Signed-off-by: Marek Vasut <marex@denx.de>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20221104160315.213836-1-marex@denx.de
Signed-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/sound/fsl,sai.yaml

@@ -18,15 +18,12 @@ description: |
 properties:
   compatible:
     oneOf:
-      - enum:
-          - fsl,vf610-sai
-          - fsl,imx6sx-sai
-          - fsl,imx6ul-sai
-          - fsl,imx7ulp-sai
-          - fsl,imx8mq-sai
-          - fsl,imx8qm-sai
-          - fsl,imx8ulp-sai
-          - fsl,imx93-sai
+      - items:
+          - enum:
+              - fsl,imx6ul-sai
+              - fsl,imx7d-sai
+          - const: fsl,imx6sx-sai
+
       - items:
           - enum:
               - fsl,imx8mm-sai
@@ -34,6 +31,15 @@ properties:
               - fsl,imx8mp-sai
           - const: fsl,imx8mq-sai
 
+      - items:
+          - enum:
+              - fsl,imx6sx-sai
+              - fsl,imx7ulp-sai
+              - fsl,imx8mq-sai
+              - fsl,imx8qm-sai
+              - fsl,imx8ulp-sai
+              - fsl,vf610-sai
+
   reg:
     maxItems: 1