net/stmmac: Move "#include <linux/platform_device.h>" to linux/stmmac.h

stmmac.h uses struct platform_device and doesn't include
<linux/platform_device.h>. Whereas drivers/net/stmmac/stmmac.h includes it, but
doesn't directly use it. And so we get following compilation warning while using
this file:
	warning: ‘struct platform_device’ declared inside parameter list

This patch includes <linux/platform_device.h> in linux/stmmac.h and removes it
from drivers/net/stmmac/stmmac.h

Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
Acked-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/stmmac/stmmac.h

@@ -21,7 +21,6 @@
 *******************************************************************************/
 
 #define DRV_MODULE_VERSION	"Nov_2010"
-#include <linux/platform_device.h>
 #include <linux/stmmac.h>
 
 #include "common.h"

include/linux/stmmac.h

@@ -26,6 +26,8 @@
 #ifndef __STMMAC_PLATFORM_DATA
 #define __STMMAC_PLATFORM_DATA
 
+#include <linux/platform_device.h>
+
 /* platform data for platform device structure's platform_data field */
 
 /* Private data for the STM on-board ethernet driver */