examples/ip_pipeline: support RSS

examples/ip_pipeline: support RSS

This patch enables rss (receive side scaling) per network interface
through the configuration file. The user can specify following
parameters in LINK section for enabling the rss feature - rss_qs,
rss_proto_ipv4, rss_proto_ipv6 and ip_proto_l2.

The "rss_qs" is mandatory parameter which indicates the queues to be
used for rss, while rest of the parameters are optional. When optional
parameters are not provided in the configuration file, default setting
(ETH_RSS_IPV4 | ETH_RSS_IPV6) is assumed for "rss_hf" field of the
rss_conf structure.

For example, following configuration can be applied for using the rss
on port 0 of the network interface;

[PIPELINE0]
type = MASTER
core = 0

[LINK0]
rss_qs = 0 1

[PIPELINE1]
type = PASS-THROUGH
core = 1
pktq_in = RXQ0.0 RXQ0.1 RXQ1.0
pktq_out = TXQ0.0 TXQ1.0 TXQ0.1

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