Add if_link.h and netlink.h UAPI headers

Add more UAPI headers from kernel tree since libbpf relies on their
latest versions that may not be present on target system to use in
build.

if_link.h and netlink.h are synced to include/uapi/linux/ from [1]

[1]
https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git/tree/tools/include/uapi/linux

Signed-off-by: Andrey Ignatov <rdna@fb.com>
3 files changed
tree: 4b07d78ed9da7a1368f371206e24eee5fe524909
  1. include/
  2. scripts/
  3. src/
  4. README