sb/intel/lynxpoint: Move IOBP API to its own compilation unit

Change-Id: Icb6114302cebe19bc3c1971929ea4fc085b454be
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/41946
Reviewed-by: Michael Niewöhner
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>
Reviewed-by: Jonathan Kollasch <jakllsch@kollasch.net>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/southbridge/intel/lynxpoint/Makefile.inc b/src/southbridge/intel/lynxpoint/Makefile.inc
index 16daa10..9694cc3 100644
--- a/src/southbridge/intel/lynxpoint/Makefile.inc
+++ b/src/southbridge/intel/lynxpoint/Makefile.inc
@@ -5,6 +5,7 @@
 bootblock-y += bootblock.c
 
 ramstage-y += pch.c
+ramstage-y += iobp.c
 ramstage-y += azalia.c
 ramstage-y += fadt.c
 ramstage-y += lpc.c