phy: atheros: fix AR8021 PHY ID mask

The upper bits are all the OUI.

Signed-off-by: Michael Walle <michael@walle.cc>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
diff --git a/drivers/net/phy/atheros.c b/drivers/net/phy/atheros.c
index 3cc1628..01953a1 100644
--- a/drivers/net/phy/atheros.c
+++ b/drivers/net/phy/atheros.c
@@ -120,7 +120,7 @@
 static struct phy_driver AR8021_driver =  {
 	.name = "AR8021",
 	.uid = 0x4dd040,
-	.mask = 0x4ffff0,
+	.mask = 0xfffffff0,
 	.features = PHY_GBIT_FEATURES,
 	.config = ar8021_config,
 	.startup = genphy_startup,