pcu_sock: add basic pcu interface support

Adds a basic version of a pcu socket interface, similar
to the one that can be found in osmo-bts.

Change-Id: Ib13cb4099d12fa71e9e0b8727e19ab29e11909b2
diff --git a/openbsc/src/libbsc/Makefile.am b/openbsc/src/libbsc/Makefile.am
index fd8f37a..e78bde6 100644
--- a/openbsc/src/libbsc/Makefile.am
+++ b/openbsc/src/libbsc/Makefile.am
@@ -36,6 +36,7 @@
 	handover_decision.c \
 	handover_logic.c \
 	meas_rep.c \
+	pcu_sock.c \
 	rest_octets.c \
 	system_information.c \
 	e1_config.c \