via-rhine: add 64bit statistics.

Switch to use ndo_get_stats64 to get 64bit statistics.

Signed-off-by: Jamie Gloudon <jamie.gloudon@gmail.com>
Tested-by: Jamie Gloudon <jamie.gloudon@gmail.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>