net: phy: fix phy_start to consider PHY_IGNORE_INTERRUPT

This condition wasn't adjusted when PHY_IGNORE_INTERRUPT (-2) was added
long ago. In case of PHY_IGNORE_INTERRUPT the MAC interrupt indicates
also PHY state changes and we should do what the symbol says.

Fixes: 84a527a4 ("net: phylib: fix interrupts re-enablement in phy_start")
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/phy/phy.c

@@ -822,7 +822,7 @@ void phy_start(struct phy_device *phydev)
 		phy_resume(phydev);
 
 		/* make sure interrupts are re-enabled for the PHY */
-		if (phydev->irq != PHY_POLL) {
+		if (phy_interrupt_is_valid(phydev)) {
 			err = phy_enable_interrupts(phydev);
 			if (err < 0)
 				break;