redhat: Add DENYLIST.rhel to BPF selftests

Upstream status: RHEL only

BPF upstream requires specific kernel configuration (defined in tools/testing/selftests/bpf/config*) for the BPF selftests to pass. RHEL does not enable some of the required options and therefore some test cases cannot pass.

Upstream uses the DENYLIST file to filter out buggy and flaky tests. To respect that, add a new file DENYLIST.rhel containing the aforementioned test cases. During RPM build, we append the file contents to the global DENYLIST that is now also copied to kernel-selftests-internal.

DENYLIST can be applied in test_progs with:

# ./test_progs -d @DENYLIST

Signed-off-by: Viktor Malik vmalik@redhat.com