tools: Sync if_link.h uapi tooling header

Sync if_link uapi header to the latest version as we need the refresher
in tooling for netkit device. Given it's been a while since the last sync
and the diff is fairly big, it has been done as its own commit.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://lore.kernel.org/r/20241004101335.117711-4-daniel@iogearbox.net
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>

Author: borkmann