Merge branch 'netkit: Add option for scrubbing skb meta data'

Daniel Borkmann says:

=====================
This series is to add a NETKIT_SCRUB_NONE mode such that
the netkit device will not scrub the skb->{mark, priority} before
running the netkit bpf prog. This will allow the netkit bpf prog to
implement different policies based on the skb->{mark, priority}.

The default mode NETKIT_SCRUB_DEFAULT will always scrub
the skb->{mark, priority} before calling the netkit bpf prog. This
is the existing behavior of the netkit device and this change
will not affect the existing netkit users.
=====================

Link: https://lore.kernel.org/r/20241004101335.117711-1-daniel@iogearbox.net
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>