net: sched: Make FIFO Qdisc offloadable

Invoke ndo_setup_tc() as appropriate to signal init / replacement,
destroying and dumping of pFIFO / bFIFO Qdisc.

A lot of the FIFO logic is used for pFIFO_head_drop as well, but that's a
semantically very different Qdisc that isn't really in the same boat as
pFIFO / bFIFO. Split some of the functions to keep the Qdisc intact.

Signed-off-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/netdevice.h

@@ -853,6 +853,7 @@ enum tc_setup_type {
 	TC_SETUP_FT,
 	TC_SETUP_QDISC_ETS,
 	TC_SETUP_QDISC_TBF,
+	TC_SETUP_QDISC_FIFO,
 };
 
 /* These structures hold the attributes of bpf state that are being passed