ethdev: introduce Rx queue offloads API

ethdev: introduce Rx queue offloads API

Introduce a new API to configure Rx offloads.

In the new API, offloads are divided into per-port and per-queue
offloads. The PMD reports capability for each of them.
Offloads are enabled using the existing DEV_RX_OFFLOAD_* flags.
To enable per-port offload, the offload should be set on both device
configuration and queue configuration. To enable per-queue offload, the
offloads can be set only on queue configuration.

Applications should set the ignore_offload_bitfield bit on rxmode
structure in order to move to the new API.

The old Rx offloads API is kept for the meanwhile, in order to enable a
smooth transition for PMDs and application to the new API.

Signed-off-by: Shahaf Shuler <shahafs@mellanox.com>
Reviewed-by: Andrew Rybchenko <arybchenko@solarflare.com>
Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>