net: freescale: fec: Fix ethtool -d runtime PM

In order to dump the FECs registers the clocks have to be ticking,
otherwise a data abort occurs.  Add calls to runtime PM so they are
enabled and later disabled.

Fixes: e8fcfcd5 ("net: fec: optimize the clock management to save power")
Reported-by: Chris Healy <Chris.Healy@zii.aero>
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/freescale/fec_main.c

@@ -2199,8 +2199,14 @@ static void fec_enet_get_regs(struct net_device *ndev,
 {
 	struct fec_enet_private *fep = netdev_priv(ndev);
 	u32 __iomem *theregs = (u32 __iomem *)fep->hwp;
+	struct device *dev = &fep->pdev->dev;
 	u32 *buf = (u32 *)regbuf;
 	u32 i, off;
+	int ret;
+
+	ret = pm_runtime_get_sync(dev);
+	if (ret < 0)
+		return;
 
 	regs->version = fec_enet_register_version;
 
@@ -2216,6 +2222,9 @@ static void fec_enet_get_regs(struct net_device *ndev,
 		off >>= 2;
 		buf[off] = readl(&theregs[off]);
 	}
+
+	pm_runtime_mark_last_busy(dev);
+	pm_runtime_put_autosuspend(dev);
 }
 
 static int fec_enet_get_ts_info(struct net_device *ndev,