hnbgw vty: add empty hnbgw and hnbgw/iuh vty nodes

Add include/osmocom/iuh/ named after this project (osmo-iuh), and add vty.h to
define VTY node enum values. Also add (to) Makefile.am and configure.ac to
include in the build.

An upcoming commit will add the actual first config item to the hnbgw/iuh node.

Change-Id: I71545823d3bd81cb888c85df8e298a56c98bf131
5 files changed