build: move headers to include/osmocom/*
This came up while fixing 'make distcheck'; this is certainly not the easiest
way but it makes sense to have the headers in include/, like we do in openbsc.
The easy alternative might be to add -I$(top_srcdir)/src to src/Makefile.am.
Remove -I$(top_srcdir)/src from src/tests/Makefile.am, no longer needed.
Change-Id: I5a82e029dcdc4df0a60a31271a4883393fe59234
diff --git a/include/osmocom/iuh/hnbgw_cn.h b/include/osmocom/iuh/hnbgw_cn.h
new file mode 100644
index 0000000..d5bec04
--- /dev/null
+++ b/include/osmocom/iuh/hnbgw_cn.h
@@ -0,0 +1,5 @@
+#pragma once
+
+#include <osmocom/iuh/hnbgw.h>
+
+struct hnbgw_cnlink *hnbgw_cnlink_init(struct hnb_gw *gw, const char *host, uint16_t port, int is_ps);