spi: dt-bindings: at91: Add sama7d65 compatible string

Add compatible string for sama7d65. Like sam9x60 and sam9x7, it requires
to bind to "atmel,at91rm9200-spi".
Group these three under the same enum, sorted alphanumerically, and
remove previously added item.
Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Acked-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://patch.msgid.link/20240711165402.373634-1-nicolas.ferre@microchip.comSigned-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/spi/atmel,at91rm9200-spi.yaml

@@ -18,10 +18,10 @@ properties:
     oneOf:
       - const: atmel,at91rm9200-spi
       - items:
-          - const: microchip,sam9x60-spi
-          - const: atmel,at91rm9200-spi
-      - items:
-          - const: microchip,sam9x7-spi
+          - enum:
+              - microchip,sam9x60-spi
+              - microchip,sam9x7-spi
+              - microchip,sama7d65-spi
           - const: atmel,at91rm9200-spi
 
   reg: