ibm/emac: fix improper cleanup when device is removed to allow re-bind

The re-binding (unbind..bind) of an EMAC device fails because the
static variable "busy_phy_map" is not updated when the device is
removed.

Signed-off-by: Wolfgang Grandegger <wg@denx.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/ibm/emac/core.c b/drivers/net/ethernet/ibm/emac/core.c
index ed79b2d..2abce96 100644
--- a/drivers/net/ethernet/ibm/emac/core.c
+++ b/drivers/net/ethernet/ibm/emac/core.c
@@ -2924,6 +2924,9 @@
 	if (emac_has_feature(dev, EMAC_FTR_HAS_ZMII))
 		zmii_detach(dev->zmii_dev, dev->zmii_port);
 
+	busy_phy_map &= ~(1 << dev->phy.address);
+	DBG(dev, "busy_phy_map now %#x" NL, busy_phy_map);
+
 	mal_unregister_commac(dev->mal, &dev->commac);
 	emac_put_deps(dev);