eventdev: add eth Tx adapter APIs

The ethernet Tx adapter abstracts the transmit stage of an
event driven packet processing application. The transmit
stage may be implemented with eventdev PMD support or use a
rte_service function implemented in the adapter. These APIs
provide a common configuration and control interface and
an transmit API for the eventdev PMD implementation.

The transmit port is specified using mbuf::port. The transmit
queue is specified using the rte_event_eth_tx_adapter_txq_set()
function.

Signed-off-by: Nikhil Rao <nikhil.rao@intel.com>
Acked-by: Jerin Jacob <jerin.jacob@caviumnetworks.com>

MAINTAINERS

@@ -378,6 +378,11 @@ F: lib/librte_eventdev/*eth_rx_adapter*
 F: test/test/test_event_eth_rx_adapter.c
 F: doc/guides/prog_guide/event_ethernet_rx_adapter.rst
 
+Eventdev Ethdev Tx Adapter API - EXPERIMENTAL
+M: Nikhil Rao <nikhil.rao@intel.com>
+T: git://dpdk.org/next/dpdk-next-eventdev
+F: lib/librte_eventdev/*eth_tx_adapter*
+
 Eventdev Timer Adapter API - EXPERIMENTAL
 M: Erik Gabriel Carrillo <erik.g.carrillo@intel.com>
 T: git://dpdk.org/next/dpdk-next-eventdev

doc/api/doxy-api-index.md

@@ -22,6 +22,7 @@ The public API headers are grouped by topics:
   [compress]           (@ref rte_comp.h),
   [eventdev]           (@ref rte_eventdev.h),
   [event_eth_rx_adapter]   (@ref rte_event_eth_rx_adapter.h),
+  [event_eth_tx_adapter]   (@ref rte_event_eth_tx_adapter.h),
   [event_timer_adapter]    (@ref rte_event_timer_adapter.h),
   [event_crypto_adapter]   (@ref rte_event_crypto_adapter.h),
   [rawdev]             (@ref rte_rawdev.h),