net: mdio-gpio: move platform data header

This header file only contains the platform data structure definition,
so move it to the include/linux/platform_data/ directory.

Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/phy/mdio-gpio.c

@@ -25,7 +25,7 @@
 #include <linux/interrupt.h>
 #include <linux/platform_device.h>
 #include <linux/gpio.h>
-#include <linux/mdio-gpio.h>
+#include <linux/platform_data/mdio-gpio.h>
 
 #include <linux/of_gpio.h>
 #include <linux/of_mdio.h>