Add rules for gen_xml and its quiet & silent variants.  This causes "make -s"
to be silent for gen_xml.
Signed-off-by: NMike Frysinger <vapier@gentoo.org>
Acked-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>