net: dsa: sja1105: move MAC configuration to .phylink_mac_link_up

The switches supported so far by the driver only have non-SerDes ports,
so they should be configured in the PHYLINK callback that provides the
resolved PHY link parameters.

Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>