gianfar: Fix warning when CONFIG_PM off

CC      drivers/net/ethernet/freescale/gianfar.o
drivers/net/ethernet/freescale/gianfar.c:568:13: warning: 'lock_tx_qs'
defined but not used [-Wunused-function]
 static void lock_tx_qs(struct gfar_private *priv)
             ^
drivers/net/ethernet/freescale/gianfar.c:576:13: warning: 'unlock_tx_qs'
defined but not used [-Wunused-function]
 static void unlock_tx_qs(struct gfar_private *priv)
             ^

Reported-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Claudiu Manoil <claudiu.manoil@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/freescale/gianfar.c b/drivers/net/ethernet/freescale/gianfar.c
index ff87502..caad327 100644
--- a/drivers/net/ethernet/freescale/gianfar.c
+++ b/drivers/net/ethernet/freescale/gianfar.c
@@ -565,6 +565,7 @@
 	}
 }
 
+#ifdef CONFIG_PM
 static void lock_tx_qs(struct gfar_private *priv)
 {
 	int i;
@@ -580,6 +581,7 @@
 	for (i = 0; i < priv->num_tx_queues; i++)
 		spin_unlock(&priv->tx_queue[i]->txlock);
 }
+#endif
 
 static int gfar_alloc_tx_queues(struct gfar_private *priv)
 {