MAINTAINERS: add missing entries for virtio

Some head files were split or moved to uapi/ without
updating MAINTAINERS.

Signed-off-by: Amos Kong <kongjianjun@gmail.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
diff --git a/MAINTAINERS b/MAINTAINERS
index e95b1e9..8a42891 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -8609,6 +8609,7 @@
 F:	drivers/net/virtio_net.c
 F:	drivers/block/virtio_blk.c
 F:	include/linux/virtio_*.h
+F:	include/uapi/linux/virtio_*.h
 
 VIRTIO HOST (VHOST)
 M:	"Michael S. Tsirkin" <mst@redhat.com>