There's no clear explanation of what VF Representors are for, their
 semantics, etc., outside of vendor docs and random conference slides.
Add a document explaining Representors and defining what drivers that
 implement them are expected to do.
Signed-off-by: NEdward Cree <ecree.xilinx@gmail.com>
Reviewed-by: NBagas Sanjaya <bagasdotme@gmail.com>
Link: https://lore.kernel.org/r/20220905135557.39233-1-ecree@xilinx.comSigned-off-by: NJakub Kicinski <kuba@kernel.org>