superio/smsc/sch5545: add support for SMSC SCH5545

The SMSC SCH5545 is very similar to the publicly available
datasheet for the SCH5627.

TEST=use PS2 keyboard and mouse, serial port, runtime registers and
Embedded Memory Interface on Dell Optiplex 9010

Signed-off-by: Michał Żygowski <michal.zygowski@3mdeb.com>
Change-Id: If8a60d5802675f09b08014ed583d2d8afa29fc04
Reviewed-on: https://review.coreboot.org/c/coreboot/+/40350
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/superio/smsc/Makefile.inc b/src/superio/smsc/Makefile.inc
index 17bdaea..9442a9e 100644
--- a/src/superio/smsc/Makefile.inc
+++ b/src/superio/smsc/Makefile.inc
@@ -16,3 +16,4 @@
 subdirs-y += smscsuperio
 subdirs-y += sio1036
 subdirs-y += sch4037
+subdirs-y += sch5545