selftests: drv-net: rss_ctx: check behavior of indirection table resizing

Some devices dynamically increase and decrease the size of the RSS
indirection table based on the number of enabled queues.
When that happens driver must maintain the balance of entries
(preferably duplicating the smaller table).

Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20240708213627.226025-5-kuba@kernel.org


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