hnbgw: move vty commands out to new hnbgw_vty.c

Pass g_hnb_gw and tall_hnb_ctx to hnbgw_vty_init() as they are no longer
statically available.

Change-Id: If85c1b97a240bd1dcf9f367ea6fca857d542ab22
diff --git a/src/Makefile.am b/src/Makefile.am
index 2d078f3..17e60e2 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -46,6 +46,7 @@
 		     rua_encoder.c rua_decoder.c rua_common.c \
 		     rua_msg_factory.c \
 		     hnbgw.c hnbgw_hnbap.c hnbgw_rua.c hnbgw_ranap.c \
+		     hnbgw_vty.c \
 		     context_map.c hnbgw_cn.c
 
 osmo_hnbgw_LDADD = $(OSMOCORE_LIBS) $(OSMOVTY_LIBS) $(OSMOGSM_LIBS) \