octeontx2-pf: TCP segmentation offload support

Adds TCP segmentation offload (TSO) support. First version
of the silicon didn't support TSO offload, for this driver
level TSO support is added.

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