dnet: remove duplicated #include

Removed duplicated #include in drivers/net/dnet.c.
Signed-off-by: Huang Weiyi <weiyi.huang@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dnet.c

@@ -21,7 +21,6 @@
 #include <linux/dma-mapping.h>
 #include <linux/platform_device.h>
 #include <linux/phy.h>
-#include <linux/platform_device.h>
 
 #include "dnet.h"