dt-bindings: iio: adc: adi,ad7606: fix example

Example uses adi,ad7606-8 as compatible, but adi,sw-mode is not
available for it. So remove this property from example.
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Guillaume Stols <gstols@baylibre.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Documentation/devicetree/bindings/iio/adc/adi,ad7606.yaml

@@ -152,7 +152,6 @@ examples:
                                            <&gpio 23 GPIO_ACTIVE_HIGH>,
                                            <&gpio 26 GPIO_ACTIVE_HIGH>;
             standby-gpios = <&gpio 24 GPIO_ACTIVE_LOW>;
-            adi,sw-mode;
         };
     };
 ...