tools: move CONFIG_DIR and XEN_CONFIG_DIR in paths.m4
Upcoming changes need to reuse XEN_CONFIG_DIR.
In its current location the assignment happens too late. Move it up
in the file, along with CONFIG_DIR. Their only dependency is
sysconfdir, which may also be adjusted in this file.
No functional change intended.
[autoconf rerun -iwj]
Signed-off-by: Olaf Hering <olaf@aepfle.de> Reviewed-by: Ian Jackson <iwj@xenproject.org> Release-Acked-by: Ian Jackson <iwj@xenproject.org>