selftests: bpf: fix legacy netfilter options

Recent commit to add NETFILTER_XTABLES_LEGACY missed setting
a couple of configs to y. They are still enabled but as modules
which appears to have upset BPF CI, e.g.:

   test_bpf_nf_ct:FAIL:iptables-legacy -t raw -A PREROUTING -j CONNMARK --set-mark 42/0 unexpected error: 768 (errno 0)

Fixes: 3c3ab65f ("selftests: net: Enable legacy netfilter legacy options.")
Link: https://patch.msgid.link/20250726155349.1161845-1-kuba@kernel.org


Signed-off-by: Jakub Kicinski <kuba@kernel.org>