libbpf: Add uprobe_multi attach type and link names

Adding new uprobe_multi attach type and link names,
so the functions can resolve the new values.

Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230809083440.3209381-8-jolsa@kernel.org


Signed-off-by: Alexei Starovoitov <ast@kernel.org>