net: stmmac: remplace asm/io.h by linux/io.h

This patch fix the checkpatch warning about asm/io.h.
Sorting all includes in the process.

Signed-off-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c

@@ -20,13 +20,13 @@
   Maintainer: Giuseppe Cavallaro <peppe.cavallaro@st.com>
 *******************************************************************************/
 
+#include <linux/io.h>
 #include <linux/mii.h>
-#include <linux/phy.h>
-#include <linux/slab.h>
 #include <linux/of.h>
 #include <linux/of_gpio.h>
 #include <linux/of_mdio.h>
-#include <asm/io.h>
+#include <linux/phy.h>
+#include <linux/slab.h>
 
 #include "stmmac.h"