selftests: net-drv: queues: sanity check netlink dumps

This test already catches a netlink bug fixed by this series,
but only when running on HW with many queues. Make sure the
netdevsim instance created has a lot of queues, and constrain
the size of the recv_buffer used by netlink.

While at it test both rx and tx queues.

Reviewed-by: Joe Damato <jdamato@fastly.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Link: https://patch.msgid.link/20241213152244.3080955-5-kuba@kernel.org


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