add xen-9p-backend to MAINTAINERS under Xen

Signed-off-by: NStefano Stabellini <sstabellini@kernel.org>
Signed-off-by: NStefano Stabellini <stefano@aporeto.com>
Reviewed-by: NGreg Kurz <groug@kaod.org>
CC: groug@kaod.org
CC: anthony.perard@citrix.com

MAINTAINERS

@@ -327,6 +327,7 @@ L: xen-devel@lists.xenproject.org
 S: Supported
 F: xen-*
 F: */xen*
+F: hw/9pfs/xen-9p-backend.c
 F: hw/char/xen_console.c
 F: hw/display/xenfb.c
 F: hw/net/xen_nic.c