tc: Add support for the matchall traffic classifier.

tc: Add support for the matchall traffic classifier.

The matchall classifier matches every packet and allows the user to apply
actions on it. In addition, it supports the skip_sw and skip_hw (as can
be found on u32 and flower filter) that direct the kernel to skip the
software/hardware processing of the actions.

This filter is very useful in usecases where every packet should be
matched. For example, packet mirroring (SPAN) can be setup very easily
using that filter.

Signed-off-by: Yotam Gigi <yotamg@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>