net/funeth: add the data path

Add the driver's data path. Tx handles skbs, XDP, and kTLS, Rx has skbs
and XDP. Also included are Rx and Tx queue creation/tear-down and
tracing.

Signed-off-by: Dimitris Michailidis <dmichail@fungible.com>
Signed-off-by: David S. Miller <davem@davemloft.net>