spi: dt-bindings: atmel,at91rm9200-spi: remove 9x60 compatible from list

Remove microchip,sam9x60-spi compatible from the list as the driver used
has the compatible atmel,at91rm9200-spi and sam9x60 devices also use the
same compatible as fallback. So removing the microchip,sam9x60-spi
compatible from the list since it is not needed.
Signed-off-by: Varshini Rajendran <varshini.rajendran@microchip.com>
Reviewed-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Link: https://msgid.link/r/20240223172638.672366-1-varshini.rajendran@microchip.comSigned-off-by: Mark Brown <broonie@kernel.org>

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

@@ -22,7 +22,6 @@ properties:
           - const: atmel,at91rm9200-spi
       - items:
           - const: microchip,sam9x7-spi
-          - const: microchip,sam9x60-spi
           - const: atmel,at91rm9200-spi
 
   reg: