selftests/bpf: Add netkit to tc_redirect selftest

Extend the existing tc_redirect selftest to also cover netkit devices
for exercising the bpf_redirect_peer() code paths, so that we have both
veth as well as netkit covered, all tests still pass after this change.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Stanislav Fomichev <sdf@google.com>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://lore.kernel.org/r/20231114004220.6495-9-daniel@iogearbox.net


Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>