net: phy: Restore phy_resume() locking assumption

commit f5e64032a799 ("net: phy: fix resume handling") changes the
locking semantics for phy_resume() such that the caller now needs to
hold the phy mutex. Not all call sites were adopted to this new
semantic, resulting in warnings from the added
WARN_ON(!mutex_is_locked(&phydev->lock)).  Rather than change the
semantics, add a __phy_resume() and restore the old behavior of
phy_resume().

Reported-by: Heiner Kallweit <hkallweit1@gmail.com>
Fixes: f5e64032a799 ("net: phy: fix resume handling")
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/phy.h b/include/linux/phy.h
index 5a0c3e5..d706953 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -924,6 +924,7 @@ void phy_device_remove(struct phy_device *phydev);
 int phy_init_hw(struct phy_device *phydev);
 int phy_suspend(struct phy_device *phydev);
 int phy_resume(struct phy_device *phydev);
+int __phy_resume(struct phy_device *phydev);
 int phy_loopback(struct phy_device *phydev, bool enable);
 struct phy_device *phy_attach(struct net_device *dev, const char *bus_id,
 			      phy_interface_t interface);