Call the rather expensive mv88e6xxx_mdios_register() at the beginning of
mv88e6xxx_setup(). This avoids the double call via mv88e6xxx_probe()
during boot.
For symmetry, call mv88e6xxx_mdios_unregister() at the end of
mv88e6xxx_teardown().
Link: https://lore.kernel.org/lkml/449bde236c08d5ab5e54abd73b645d8b29955894.camel@xxxxxxxxx/
Suggested-by: Andrew Lunn <andrew@xxxxxxx>
Signed-off-by: Klaus Kudielka <klaus.kudielka@xxxxxxxxx>
Reviewed-by: Andrew Lunn <andrew@xxxxxxx>