superio/smsc/lpc47n207: Hook into build system

Provide proper Makefile and Kconfig components so
that this superio is built as object code. Select
superio component in mainboard Kconfig's to bring
in the link-time symbols and thereby removing the
need for .c inclusion.

N.B. The LPC47N207 Super I/O does not physically exist
on these boards. The Super I/O is found on external LPC
debug card hardware and so should really be made selectable.
However, this is beyond the scope of this specific fix, that
rids us of .c inclusions in romstage.c

Change-Id: I451c3a81c4b5beca1ed65e27467a7393d2521dae
Signed-off-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>
Reviewed-on: http://review.coreboot.org/8084
Tested-by: build bot (Jenkins)
Reviewed-by: Marc Jones <marc.jones@se-eng.com>
diff --git a/src/superio/smsc/Kconfig b/src/superio/smsc/Kconfig
index 6aaa112..34bc60c 100644
--- a/src/superio/smsc/Kconfig
+++ b/src/superio/smsc/Kconfig
@@ -30,6 +30,8 @@
 	bool
 config SUPERIO_SMSC_LPC47M15X
 	bool
+config SUPERIO_SMSC_LPC47N207
+	bool
 config SUPERIO_SMSC_LPC47N217
 	bool
 config SUPERIO_SMSC_LPC47N227