fix api changes in xen restore

fix api changes in xen restore

in recently xen commit: 7051d5c8, there is a api changes in
libxl_domain_create_restore.
Author: Andrew Cooper <andrew.cooper3@citrix.com>
Date:   Thu Oct 10 12:23:10 2013 +0100

    tools/migrate: Fix regression when migrating from older version of Xen

use the macro LIBXL_HAVE_DOMAIN_CREATE_RESTORE_PARAMS in libxl.h
in order to make libvirt could compile with old and new xen.

the params checkpointed_stream is useful if libvirt libxl driver
support migration. for new, set it as zero.

Signed-off-by: Bamvor Jian Zhang <bjzhang@suse.com>