arc_emac: add clock handling

This adds ability for the arc_emac to really handle its supplying clock.
To get the needed clock-frequency either a real clock or the previous
clock-frequency property must be provided.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Max Schwarz <max.schwarz@online.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/arc/emac.h b/drivers/net/ethernet/arc/emac.h
index 928fac6..53f85bf 100644
--- a/drivers/net/ethernet/arc/emac.h
+++ b/drivers/net/ethernet/arc/emac.h
@@ -11,6 +11,7 @@
 #include <linux/dma-mapping.h>
 #include <linux/netdevice.h>
 #include <linux/phy.h>
+#include <linux/clk.h>
 
 /* STATUS and ENABLE Register bit masks */
 #define TXINT_MASK	(1<<0)	/* Transmit interrupt */
@@ -131,6 +132,7 @@
 	struct mii_bus *bus;
 
 	void __iomem *regs;
+	struct clk *clk;
 
 	struct napi_struct napi;
 	struct net_device_stats stats;