ASoC: dt-bindings: atmel-classd: add sam9x7 compatible

Add sam9x7 compatible to DT bindings documentation.
Signed-off-by: Varshini Rajendran <varshini.rajendran@microchip.com>
Link: https://lore.kernel.org/r/20240223172608.672190-1-varshini.rajendran@microchip.comSigned-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/sound/atmel,sama5d2-classd.yaml

@@ -18,7 +18,12 @@ description:
 
 properties:
   compatible:
-    const: atmel,sama5d2-classd
+    oneOf:
+      - items:
+          - const: atmel,sama5d2-classd
+      - items:
+          - const: microchip,sam9x7-classd
+          - const: atmel,sama5d2-classd
 
   reg:
     maxItems: 1