net: dsa: microchip: Setup fiber ports for KSZ8463

The fiber ports in KSZ8463 cannot be detected internally, so it requires
specifying that condition in the device tree.  Like the one used in
Micrel PHY the port link can only be read and there is no write to the
PHY.  The driver programs registers to operate fiber ports correctly.

Signed-off-by: Tristram Ha <tristram.ha@microchip.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://patch.msgid.link/20250725001753.6330-6-Tristram.Ha@microchip.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>