ethdev: support encapsulation level for RSS offload
ethdev: support encapsulation level for RSS offload

This patch reserves 2 bits as input selection to select inner and outer
encapsulation level for RSS computation. It is combined with existing
ETH_RSS_* to choose inner or outer layers.
This functionality already exists in rte_flow through level parameter in
RSS action configuration rte_flow_action_rss.

Signed-off-by: Kiran Kumar K <e1300a447d3f51462b9608d40060b5f05b85c806@marvell.com>
Acked-by: Andrew Rybchenko <ac94ab2a8fe9a9a087f6e24dcbc16626b52c07e8@solarflare.com>
Reviewed-by: Ajit Khaparde <01965fbd61169dc18f3fb5e13de7f67d298f8924@broadcom.com>

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