aquantia: Do not purge addresses when setting the number of rings

IPV6 addresses are purged when setting the number of rx/tx
rings using ethtool -G. The function aq_set_ringparam
calls dev_close, which removes the addresses. As a solution,
call an internal function (aq_ndev_close).

Fixes: c1af5427 ("net: aquantia: Ethtool based ring size configuration")
Signed-off-by: Izabela Bakollari <ibakolla@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>