app/testpmd: add traffic management forwarding mode

app/testpmd: add traffic management forwarding mode

This commit extends the testpmd application with new forwarding engine
that demonstrates the use of ethdev traffic management APIs and softnic
PMD for QoS traffic management.

In this mode, 5-level hierarchical tree of the QoS scheduler is built
with the help of ethdev TM APIs such as shaper profile add/delete,
shared shaper add/update, node add/delete, hierarchy commit, etc.
The hierarchical tree has following nodes; root node(x1, level 0),
subport node(x1, level 1), pipe node(x4096, level 2),
tc node(x16348, level 3), queue node(x65536, level 4).

During runtime, each received packet is first classified by mapping the
packet fields information to 5-tuples (HQoS subport, pipe, traffic class,
queue within traffic class, and color) and storing it in the packet mbuf
sched field. After classification, each packet is sent to softnic port
which prioritizes the transmission of the received packets, and
accordingly sends them on to the output interface.

To enable traffic management mode, following testpmd command is used;

$ ./testpmd -c c -n 4 --vdev
	'net_softnic0,hard_name=0000:06:00.1,soft_tm=on' -- -i
	--forward-mode=tm

Signed-off-by: Jasvinder Singh <jasvinder.singh@intel.com>
Acked-by: Cristian Dumitrescu <cristian.dumitrescu@intel.com>
Acked-by: Thomas Monjalon <thomas@monjalon.net>