net: sched: mq: add simple offload notification

mq offload is trivial, we just need to let the device know
that the root qdisc is mq.  Alternative approach would be
to export qdisc_lookup() and make drivers check the root
type themselves, but notification via ndo_setup_tc is more
in line with other qdiscs.

Note that mq doesn't hold any stats on it's own, it just
adds up stats of its children.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index f45b1a4..6b863ed 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -791,6 +791,7 @@ enum tc_setup_type {
 	TC_SETUP_QDISC_CBS,
 	TC_SETUP_QDISC_RED,
 	TC_SETUP_QDISC_PRIO,
+	TC_SETUP_QDISC_MQ,
 };
 
 /* These structures hold the attributes of bpf state that are being passed