superio/smsc/lpc47b272: Use link-time symbols over .c inclusion

Change-Id: Id3d5f2a120c0a933c031102f206829305da20f0c
Signed-off-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>
Reviewed-on: http://review.coreboot.org/8081
Tested-by: build bot (Jenkins)
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
4 files changed