netdev/phy: Make get_phy_id() static and quit EXPORTing it.

This function is only referenced from within phy_device.c, so there is
no reason to export it. In fact, we can make it static.

Signed-off-by: David Daney <[e-mail]>
Acked-by: Paul Gortmaker <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/net/phy/phy_device.c

···
  * Description: Reads the ID registers of the PHY at @addr on the
  *   @bus, stores it in @phy_id and returns zero on success.
  */
-int get_phy_id(struct mii_bus *bus, int addr, u32 *phy_id)
+static int get_phy_id(struct mii_bus *bus, int addr, u32 *phy_id)
 {
 	int phy_reg;
 
···
 
 	return 0;
 }
-EXPORT_SYMBOL(get_phy_id);
 
 /**
  * get_phy_device - reads the specified PHY device and returns its @phy_device struct

include/linux/phy.h

···
 	return mdiobus_write(phydev->bus, phydev->addr, regnum, val);
 }
 
-int get_phy_id(struct mii_bus *bus, int addr, u32 *phy_id);
 struct phy_device* get_phy_device(struct mii_bus *bus, int addr);
 int phy_device_register(struct phy_device *phy);
 int phy_init_hw(struct phy_device *phydev);