ASoC: dt-bindings: maxim,max9867: fix example

Remove the common clock node from the example as suggested by
Krzysztof Kozlowski in [1].

[1] https://lore.kernel.org/lkml/45d306d3-8efb-12ac-0a83-f01ca2982b0a@linaro.org/Signed-off-by: Richard Leitner <richard.leitner@linux.dev>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20230328-max9867_dt_example_fix-v1-1-cdf31c3fdfc8@linux.devSigned-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/sound/maxim,max9867.yaml

@@ -57,10 +57,4 @@ examples:
             clocks = <&codec_clk>;
         };
     };
-
-    codec_clk: clock {
-        compatible = "fixed-clock";
-        #clock-cells = <0>;
-        clock-frequency = <12288000>;
-    };
 ...