selftests/bpf: Copy over libbpf configs

This change integrates libbpf maintained configurations and black/white
lists [0] into the repository, co-located with the BPF selftests themselves.
We minimize the kernel configurations to keep future updates as small as
possible [1].

Furthermore, we make both kernel configurations build on top of the existing
configuration tools/testing/selftests/bpf/config (to be concatenated before
build). Lastly, we replaced the terms blacklist & whitelist with denylist and
allowlist, respectively.

  [0] https://github.com/libbpf/libbpf/tree/20f03302350a4143825cedcbd210c4d7112c1898/travis-ci/vmtest/configs
  [1] https://lore.kernel.org/bpf/20220712212124.3180314-1-deso@posteo.net/T/#m30a53648352ed494e556ac003042a9ad0a8f98c6

Signed-off-by: Daniel Müller <deso@posteo.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Mykola Lysenko <mykolal@fb.com>
Link: https://lore.kernel.org/bpf/20220727001156.3553701-3-deso@posteo.net