net: phy: Restore phy_resume() locking assumption

commit f5e64032a7 ("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: f5e64032a7 ("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>

drivers/net/phy/phy.c

@@ -819,7 +819,7 @@ void phy_start(struct phy_device *phydev)
 		break;
 	case PHY_HALTED:
 		/* if phy was suspended, bring the physical link up again */
-		phy_resume(phydev);
+		__phy_resume(phydev);
 
 		/* make sure interrupts are re-enabled for the PHY */
 		if (phy_interrupt_is_valid(phydev)) {