ethdev: remove old offload API

ethdev: remove old offload API

In DPDK 17.11, the ethdev offloads API has changed:
	commit cba7f53b717d ("ethdev: introduce Tx queue offloads API")
	commit ce17eddefc20 ("ethdev: introduce Rx queue offloads API")
The new API is documented in the programmer's guide:
	http://doc.dpdk.org/guides/prog_guide/poll_mode_drv.html#hardware-offload

For reminder, the main concepts in the new API were:
	- All offloads are disabled by default
	- Distinction between per port and per queue offloads.

The transition bits are now removed:
	- Translation of the old API in ethdev
	- rte_eth_conf.rxmode.ignore_offload_bitfield
	- ETH_TXQ_FLAGS_IGNORE

The old API bits are now removed:
	- Rx per-port rte_eth_conf.rxmode.[bit-fields]
	- Tx per-queue rte_eth_txconf.txq_flags
	- ETH_TXQ_FLAGS_NO*

Signed-off-by: Ferruh Yigit <ferruh.yigit@intel.com>
Signed-off-by: Thomas Monjalon <thomas@monjalon.net>
Reviewed-by: Andrew Rybchenko <arybchenko@solarflare.com>
Reviewed-by: Shahaf Shuler <shahafs@mellanox.com>