net/sfc: support jump flows in tunnel offload

net/sfc: support jump flows in tunnel offload

JUMP is an in-house term for so-called "tunnel_set" flows. On parsing,
they are identified by virtue of actions MARK (PMD-internal) and JUMP.
The action MARK associates a given flow with its tunnel context.

Such a flow is represented by a MAE outer rule (OR) which has its
recirculation ID set. This ID is also associated with the tunnel
context. The OR is supposed to set this ID in 8 high bits of
Rx mark in matching packets. It also counts the packets.

Packets that hit the OR but miss in action rule (AR) table,
should go to MAE admin PF (that is, to DPDK) by default.

Support for the use of action COUNT in JUMP
flows will be introduced by later patches.

Signed-off-by: Ivan Malov <ivan.malov@oktetlabs.ru>
Reviewed-by: Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>