mainboard: Clear up remaining SIO_PORT from Kconfig

Push back any board specific values back into romstage.c #defines and
drop any remaining fragments of CONFIG_SIO_PORT in-tree.

Change-Id: Ieb63fb0c2ab1a82b53bafd86686de7b21ac226c3
Signed-off-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>
Reviewed-on: http://review.coreboot.org/6045
Tested-by: build bot (Jenkins)
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
12 files changed