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/mmc.h b/drivers/net/ethernet/stmicro/stmmac/mmc.h
index a3835202..67995ef 100644
--- a/drivers/net/ethernet/stmicro/stmmac/mmc.h
+++ b/drivers/net/ethernet/stmicro/stmmac/mmc.h
@@ -22,6 +22,9 @@
   Author: Giuseppe Cavallaro <peppe.cavallaro@st.com>
 *******************************************************************************/
 
+#ifndef __MMC_H__
+#define __MMC_H__
+
 /* MMC control register */
 /* When set, all counter are reset */
 #define MMC_CNTRL_COUNTER_RESET		0x1
@@ -129,3 +132,5 @@
 extern void dwmac_mmc_ctrl(void __iomem *ioaddr, unsigned int mode);
 extern void dwmac_mmc_intr_all_mask(void __iomem *ioaddr);
 extern void dwmac_mmc_read(void __iomem *ioaddr, struct stmmac_counters *mmc);
+
+#endif /* __MMC_H__ */