libbpf: capture value in BTF type info for BTF-defined map defs
Change BTF-defined map definitions to capture compile-time integer
values as part of BTF type definition, to avoid split of key/value type
information and actual type/size/flags initialization for maps.
Signed-off-by: Andrii Nakryiko <andriin@fb.com> Acked-by: Song Liu <songliubraving@fb.com> Acked-by: Yonghong Song <yhs@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>