alx: Reset phy speed after resume

This fixes bug 62491 (https://bugzilla.kernel.org/show_bug.cgi?id=62491).
After resuming some users got the following error flooding the kernel log:
alx 0000:02:00.0: invalid PHY speed/duplex: 0xffff
Signed-off-by: NJonas Hahnfeld <linux@hahnjo.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/atheros/alx/main.c

@@ -1388,6 +1388,9 @@ static int alx_resume(struct device *dev)
 {
 	struct pci_dev *pdev = to_pci_dev(dev);
 	struct alx_priv *alx = pci_get_drvdata(pdev);
+	struct alx_hw *hw = &alx->hw;
+
+	alx_reset_phy(hw);
 
 	if (!netif_running(alx->dev))
 		return 0;