net: phy: micrel: add Microchip KSZ 9477 to the device table

PHY_ID_KSZ9477 was supported but not added to the device table passed to
MODULE_DEVICE_TABLE.

Fixes: fc3973a1

 ("phy: micrel: add Microchip KSZ 9477 Switch PHY support")
Signed-off-by: Enguerrand de Ribaucourt <enguerrand.de-ribaucourt@savoirfairelinux.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>