Merge branch 'ethtool-generate-uapi-header-from-the-spec'

Stanislav Fomichev says:

====================
ethtool: generate uapi header from the spec

We keep expanding ethtool netlink api surface and this leads to
constantly playing catchup on the ynl spec side. There are a couple
of things that prevent us from fully converting to generating
the header from the spec (stats and cable tests), but we can
generate 95% of the header which is still better than maintaining
c header and spec separately. The series adds a couple of missing
features on the ynl-gen-c side and separates the parts
that we can generate into new ethtool_netlink_generated.h.
====================

Link: https://patch.msgid.link/20241204155549.641348-1-sdf@fomichev.me
Signed-off-by: Jakub Kicinski <kuba@kernel.org>