stmmac: add header inclusion protection

This patch adds "#ifndef __<header>_H" for protecting header from double
inclusion.

Signed-off-by: Rayagond Kokatanur <rayagond@vayavyalabs.com>
Hacked-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac1000.h b/drivers/net/ethernet/stmicro/stmmac/dwmac1000.h
index b4c44a5..0e4cace 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac1000.h
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac1000.h
@@ -19,6 +19,8 @@
 
   Author: Giuseppe Cavallaro <peppe.cavallaro@st.com>
 *******************************************************************************/
+#ifndef __DWMAC1000_H__
+#define __DWMAC1000_H__
 
 #include <linux/phy.h>
 #include "common.h"
@@ -232,3 +234,4 @@
 #define	DWMAC_CORE_3_40	0x34
 
 extern const struct stmmac_dma_ops dwmac1000_dma_ops;
+#endif /* __DWMAC1000_H__ */