octeontx2-pf: Add ndo_get_stats64

Added ndo_get_stats64 which returns stats maintained by HW.

Signed-off-by: Geetha sowjanya <gakula@marvell.com>
Signed-off-by: Sunil Goutham <sgoutham@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>