drivers: net: cpsw: fix compilation error with cpsw driver

drivers/net/ethernet/ti/cpsw.c: In function 'cpsw_suspend':
drivers/net/ethernet/ti/cpsw.c:1979:26: error: 'priv' undeclared (first use in this function)
drivers/net/ethernet/ti/cpsw.c:1979:26: note: each undeclared identifier is reported only once for each function it appears in
make[4]: *** [drivers/net/ethernet/ti/cpsw.o] Error 1

The compilation error was introduced by the following commit
6d3d76f8 (drivers: net: cpsw: fix cpsw clock gating issue across suspend/resume)
Signed-off-by: Mugunthan V N <mugunthanvnm@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/ti/cpsw.c

@@ -1973,6 +1973,7 @@ static int cpsw_suspend(struct device *dev)
 {
 	struct platform_device	*pdev = to_platform_device(dev);
 	struct net_device	*ndev = platform_get_drvdata(pdev);
+	struct cpsw_priv	*priv = netdev_priv(ndev);
 
 	if (netif_running(ndev))
 		cpsw_ndo_stop(ndev);