nat: Fix compilation with nat not being enabled.
common_vty.c was including bsc_nat.h which tried to
get the sccp/sccp_types.h which is not required to be
installed. Move all structs using/embedding SCCP structures
into the bsc_nat_sccp.h and include. This should fix
the compilation.
diff --git a/openbsc/src/nat/bsc_nat.c b/openbsc/src/nat/bsc_nat.c
index 0a37193..b47d7ce 100644
--- a/openbsc/src/nat/bsc_nat.c
+++ b/openbsc/src/nat/bsc_nat.c
@@ -39,6 +39,7 @@
#include <openbsc/debug.h>
#include <openbsc/bsc_msc.h>
#include <openbsc/bsc_nat.h>
+#include <openbsc/bsc_nat_sccp.h>
#include <openbsc/ipaccess.h>
#include <openbsc/abis_nm.h>
#include <openbsc/vty.h>