net: dsa: mxl862xx: rename MDIO op arguments

net: dsa: mxl862xx: rename MDIO op arguments

The use of the 'port' argument name for functions implementing the MDIO
bus operations is misleading as the port address isn't equal to the
PHY address.

Rename the MDIO operation argument name to match the prototypes of
mdiobus_write, mdiobus_read, mdiobus_c45_read and mdiobus_c45_write.

Suggested-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://patch.msgid.link/e1f4cb3bcffc7df9af0f2c9b673b14c7e1201c9a.1772507674.git.daniel@makrotopia.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>