examples/eventdev: add new Rx RSS hash offload
examples/eventdev: add new Rx RSS hash offload

Since pipeline_generic uses `rte_mbuf::hash::rss` add the new Rx offload
flag `DEV_RX_OFFLOAD_RSS_HASH` to inform PMD to copy the RSS hash result
into the mbuf.

Signed-off-by: Pavan Nikhilesh <8184a94f8f7778086ea0697cdb513b2e42813b09@marvell.com>
Reviewed-by: Ferruh Yigit <ba8734c3c506d2e3557bd4ac8fdaccd25bdb9aa7@intel.com>

john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk