net: phy: initialise phydev speed and duplex sanely

[ Upstream commit a5d66f810061e2dd70fb7a108dcd14e535bc639f ]

When a phydev is created, the speed and duplex are set to zero and
-1 respectively, rather than using the predefined SPEED_UNKNOWN and
DUPLEX_UNKNOWN constants.

There is a window at initialisation time where we may report link
down using the 0/-1 values.  Tidy this up and use the predefined
constants, so debug doesn't complain with:

"Unsupported (update phy-core.c)/Unsupported (update phy-core.c)"

when the speed and duplex settings are printed.
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

drivers/net/phy/phy_device.c

@@ -420,8 +420,8 @@ struct phy_device *phy_device_create(struct mii_bus *bus, int addr, int phy_id,
 	mdiodev->device_free = phy_mdio_device_free;
 	mdiodev->device_remove = phy_mdio_device_remove;
 
-	dev->speed = 0;
-	dev->duplex = -1;
+	dev->speed = SPEED_UNKNOWN;
+	dev->duplex = DUPLEX_UNKNOWN;
 	dev->pause = 0;
 	dev->asym_pause = 0;
 	dev->link = 0;