phylib: Make PHYs children of their MDIO bus, not the bus' parent.

commit 18ee49ddb0 ("phylib: rename mii_bus::dev to mii_bus::parent")
changed the parent of PHY devices from the bus to the bus parent.

Then, commit 4dea547fef ("phylib: rework to prepare for OF
registration of PHYs") moved the code into phy_device.c

At this point, it is somewhat unclear why the change was seen as
necessary.  But, when we look at the device model tree in
/sys/devices, it is clearly incorrect.  The PHYs should be children of
their MDIO bus.

Change the PHY's parent device to be the MDIO bus device.

Cc: Lennert Buytenhek <buytenh@wantstofly.org>
Cc: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: David Daney <david.daney@cavium.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/phy/phy_device.c

@@ -176,7 +176,7 @@ struct phy_device *phy_device_create(struct mii_bus *bus, int addr, int phy_id,
 	if (c45_ids)
 		dev->c45_ids = *c45_ids;
 	dev->bus = bus;
-	dev->dev.parent = bus->parent;
+	dev->dev.parent = &bus->dev;
 	dev->dev.bus = &mdio_bus_type;
 	dev->irq = bus->irq != NULL ? bus->irq[addr] : PHY_POLL;
 	dev_set_name(&dev->dev, PHY_ID_FMT, bus->id, addr);