dt-bindings: dwmac: Remove unexpected item.

Remove the unexpected "snps,dwmac" item in the example.

Fixes: 3b840106 ("dt-bindings: dwmac: Add bindings for new Ingenic SoCs.")
Signed-off-by: 周琰杰 (Zhou Yanjie) <zhouyanjie@wanyeetech.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/devicetree/bindings/net/ingenic,mac.yaml

@@ -61,7 +61,7 @@ examples:
     #include <dt-bindings/clock/x1000-cgu.h>
 
     mac: ethernet@134b0000 {
-        compatible = "ingenic,x1000-mac", "snps,dwmac";
+        compatible = "ingenic,x1000-mac";
         reg = <0x134b0000 0x2000>;
 
         interrupt-parent = <&intc>;