ASoC: dt-bindings: microchip: add sam9x7

Add sam9x7 compatible in the DT documentation.

Signed-off-by: Varshini Rajendran <[e-mail]>
Acked-by: Conor Dooley <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Mark Brown <[e-mail]>

Documentation/devicetree/bindings/sound/microchip,sama7g5-i2smcc.yaml

···
     const: 0
 
   compatible:
-    enum:
-      - microchip,sam9x60-i2smcc
-      - microchip,sama7g5-i2smcc
+    oneOf:
+      - enum:
+          - microchip,sam9x60-i2smcc
+          - microchip,sama7g5-i2smcc
+      - items:
+          - enum:
+              - microchip,sam9x7-i2smcc
+          - const: microchip,sam9x60-i2smcc
 
   reg:
     maxItems: 1