net/bonding: fix exported symbol versioning

net/bonding: fix exported symbol versioning

The older versions of rte_eth_bond_8023ad_conf_get and
rte_eth_bond_8023ad_setup were available in the old way since 2.0 - at
least according to the map file.

But versioning in the code was set to 16.04.
That breaks compatibility checks for 2.0 on that library.

For example with the dpdk abi checker:
http://people.canonical.com/~paelzer/compat_report.html

To fix, version the old symbols on the 2.0 version as they were
initially added to the map file.

See http://people.canonical.com/~paelzer/compat_report.html

Fixes: dc40f17a ("net/bonding: allow external state machine in mode 4")

Signed-off-by: Christian Ehrhardt <christian.ehrhardt@canonical.com>