Merge branch 'net-phy-fix-WoL-handling-when-suspending-the-PHY'

Heiner Kallweit says:

====================
net: phy: fix WoL handling when suspending the PHY

phy_suspend doesn't always recognize that WoL is enabled and therefore
suspends the PHY when it should not. First idea to address the issue
was to reuse checks used in mdio_bus_phy_may_suspend which check
whether relevant devices are wakeup-enabled.
Florian raised some concerns because drivers may enable wakeup even if
WoL isn't enabled (e.g. certain USB network drivers).

The new approach focuses on reducing the risk to break existing stuff.
We add a flag wol_enabled to struct net_device which is set in
ethtool_set_wol(). Then this flag is checked in phy_suspend().
This doesn't cover 100% of the cases yet (e.g. if WoL is enabled w/o
explicit configuration), but it covers the most relevant cases with
very little risk of regressions.

v2:
- Fix a typo
====================

Signed-off-by: David S. Miller <davem@davemloft.net>