Revert "phy dp83867: Fix compilation with CONFIG_OF_MDIO=m"

This reverts commit 7f32541c2fdaa84af418c3e1431bbd066ab44d09.

This needs reverting too, as per requests.

Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/phy/dp83867.c b/drivers/net/phy/dp83867.c
index 94cc278..2afa61b 100644
--- a/drivers/net/phy/dp83867.c
+++ b/drivers/net/phy/dp83867.c
@@ -99,7 +99,7 @@
 	return phy_write(phydev, MII_DP83867_MICR, micr_status);
 }
 
-#if IS_ENABLED(CONFIG_OF_MDIO)
+#ifdef CONFIG_OF_MDIO
 static int dp83867_of_init(struct phy_device *phydev)
 {
 	struct dp83867_private *dp83867 = phydev->priv;