selftests: drv-net-hw: Add a test for symmetric RSS hash

Add a selftest that verifies symmetric RSS hash is working as intended.
The test runs iterations of traffic, swapping the src/dst UDP ports, and
verifies that the same RX queue is receiving the traffic in both cases.

Reviewed-by: Nimrod Oren <noren@nvidia.com>
Signed-off-by: Gal Pressman <gal@nvidia.com>
Link: https://patch.msgid.link/20250224174416.499070-5-gal@nvidia.com


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