net: phy: Fix sfp.c build against GPIO definitions

include/gpio.h does not contain the references we want, we should be including
linux/gpio/consumer.h instead.

Fixes: 73970055 ("sfp: add SFP module support")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/phy/sfp.c

 #include <linux/delay.h>
-#include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
 #include <linux/i2c.h>
 #include <linux/interrupt.h>
 #include <linux/jiffies.h>