ethtool: remove the comments that are not gonna be generated

Cleanup the header manually to make it easier to review the changes that ynl
generator brings in. No functional changes.

Signed-off-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20241204155549.641348-8-sdf@fomichev.me


Signed-off-by: Jakub Kicinski <kuba@kernel.org>