mesh: Add sample JSON files to EXTRA_DIST

This adds mesh/local_node.json and mesh/prov_db.json samples
to be included with dist tarball.
diff --git a/Makefile.tools b/Makefile.tools
index 71d083e..c2d81a8 100644
--- a/Makefile.tools
+++ b/Makefile.tools
@@ -32,6 +32,8 @@
 mesh_meshctl_LDADD = gdbus/libgdbus-internal.la src/libshared-glib.la \
 				lib/libbluetooth-internal.la \
 				@GLIB_LIBS@ @DBUS_LIBS@ -ljson-c -lreadline
+
+EXTRA_DIST += mesh/local_node.json mesh/prov_db.json
 endif
 
 if MONITOR