mtp: Move the link testing into a new file for mtp_link

The link testing should work under the linkset and if the
SLTM is failing the link should be taken down and it should
be restarted.
diff --git a/src/Makefile.am b/src/Makefile.am
index eb6ab11..defe121 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -11,17 +11,19 @@
 
 cellmgr_ng_SOURCES = main.c mtp_layer3.c thread.c input/ipaccess.c pcap.c \
 		     bss_patch.c bssap_sccp.c bsc_sccp.c bsc_ussd.c links.c \
-		     msc_conn.c link_udp.c snmp_mtp.c debug.c vty_interface.c isup.c
+		     msc_conn.c link_udp.c snmp_mtp.c debug.c vty_interface.c isup.c \
+		     mtp_link.c
 cellmgr_ng_LDADD = $(LIBOSMOCORE_LIBS) $(LIBOSMOSCCP_LIBS) $(LIBOSMOVTY_LIBS) $(NEXUSWARE_C7_LIBS) \
 		   -lpthread -lnetsnmp -lcrypto
 
 udt_relay_SOURCES = main_udt.c mtp_layer3.c thread.c input/ipaccess.c pcap.c \
 		     msc_conn.c link_udp.c snmp_mtp.c debug.c vty_interface.c \
-		     bss_patch.c isup.c links.c sctp_m2ua.c
+		     bss_patch.c isup.c links.c sctp_m2ua.c mtp_link.c
 udt_relay_LDADD = $(LIBOSMOCORE_LIBS) $(LIBOSMOSCCP_LIBS) $(LIBOSMOVTY_LIBS) $(NEXUSWARE_C7_LIBS) \
 		   -lpthread -lnetsnmp -lcrypto -lm2ua -lsctp
 
 osmo_stp_SOURCES = main_stp.c mtp_layer3.c thread.c pcap.c link_udp.c snmp_mtp.c \
-		   debug.c vty_interface.c links.c isup.c sctp_m2ua.c
+		   debug.c vty_interface.c links.c isup.c sctp_m2ua.c \
+		   mtp_link.c
 osmo_stp_LDADD = $(LIBOSMOCORE_LIBS) $(LIBOSMOSCCP_LIBS) $(LIBOSMOVTY_LIBS) $(NEXUSWARE_C7_LIBS) \
 		   -lpthread -lnetsnmp -lcrypto -lm2ua -lsctp