net/bonding: provide default Rx/Tx configuration

net/bonding: provide default Rx/Tx configuration

Default Rx/Tx configuration has become a helpful
resource for applications relying on the optimal
values to make rte_eth_rxconf and rte_eth_txconf
structures. These structures can then be tweaked.

Default configuration is also used internally by
rte_eth_rx_queue_setup or rte_eth_tx_queue_setup
API calls when NULL pointer is passed by callers
with the argument for custom queue configuration.

The use cases of bonding driver may also benefit
from exercising default settings in the same way.

Restructure the code to collect various settings
from slave ports and make it possible to combine
default Rx/Tx configuration of these devices and
report it to the callers of rte_eth_dev_info_get.

Signed-off-by: Ivan Malov <ivan.malov@oktetlabs.ru>
Signed-off-by: Andrew Rybchenko <arybchenko@solarflare.com>
Acked-by: Chas Williams <chas3@att.com>