fec: Handle the regulator in suspend/resume

In order to save power, let's disable the regulator in the suspend function and
enable it in resume.

Tested on a mx28evk board.
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/freescale/fec_main.c

@@ -2044,6 +2044,9 @@ fec_suspend(struct device *dev)
 	clk_disable_unprepare(fep->clk_ahb);
 	clk_disable_unprepare(fep->clk_ipg);
 
+	if (fep->reg_phy)
+		regulator_disable(fep->reg_phy);
+
 	return 0;
 }
 
@@ -2052,6 +2055,13 @@ fec_resume(struct device *dev)
 {
 	struct net_device *ndev = dev_get_drvdata(dev);
 	struct fec_enet_private *fep = netdev_priv(ndev);
+	int ret;
+
+	if (fep->reg_phy) {
+		ret = regulator_enable(fep->reg_phy);
+		if (ret)
+			return ret;
+	}
 
 	clk_prepare_enable(fep->clk_enet_out);
 	clk_prepare_enable(fep->clk_ahb);