phylib: factor out get_phy_id from within get_phy_device

We were already doing what amounts to a get_phy_id from within
get_phy_device, and rather than duplicate this for the TBIPA
probing, we might as well just factor it out and make it available
instead.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Acked-by: Andy Fleming <afleming@freescale.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
diff --git a/include/linux/phy.h b/include/linux/phy.h
index 2d83844..779cbcd 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -381,6 +381,7 @@
 
 int phy_read(struct phy_device *phydev, u16 regnum);
 int phy_write(struct phy_device *phydev, u16 regnum, u16 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_clear_interrupt(struct phy_device *phydev);
 int phy_config_interrupt(struct phy_device *phydev, u32 interrupts);