Merge branch 'tc-sw-only'

John Fastabend says:

====================
tc software only

This adds a software only flag to tc but incorporates a bunch of comments
from the original attempt at this.

First instead of having the offload decision logic be embedded in cls_u32
I lifted into cls_pkt.h so it can be used anywhere and named the flag
TCA_CLS_FLAGS_SKIP_HW (Thanks Jiri ;)

In order to do this I put the flag defines in pkt_cls.h as well. However
it was suggested that perhaps these flags could be lifted into the
upper layer of TCA_ as well but I'm afraid this can not be done with
existing tc design as far as I can tell. The problem is the filters are
packed and unpacked in the classifier specific code and pushing the flags
through the high level doesn't seem easily doable. And we already have
this design where classifiers handle generic options such as actions and
policers. So I think adding one more thing here is OK as 'tc', et. al.
already know how to handle this type of thing.
====================

Acked-by: Pravin B Shelar <pshelar@ovn.org>
Signed-off-by: David S. Miller <davem@davemloft.net>