bpf, libbpf: Enable get{peer, sock}name attach types

Trivial patch to add the new get{peer,sock}name attach types to the section
definitions in order to hook them up to sock_addr cgroup program type.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Andrey Ignatov <rdna@fb.com>
Link: https://lore.kernel.org/bpf/7fcd4b1e41a8ebb364754a5975c75a7795051bd2.1589841594.git.daniel@iogearbox.net