vsock/test: add '--peer-port' input argument

Implement port for given CID as input argument instead of using
hardcoded value '1234'. This allows to run different test instances
on a single CID. Port argument is not required parameter and if it is
not set, then default value will be '1234' - thus we preserve previous
behaviour.

Signed-off-by: Arseniy Krasnov <avkrasnov@salutedevices.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Link: https://lore.kernel.org/r/20240123072750.4084181-1-avkrasnov@salutedevices.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

test/vsock: io_uring rx/tx tests

This adds set of tests which use io_uring for rx/tx. This test suite is
implemented as separated util like 'vsock_test' and has the same set of
input arguments as 'vsock_test'. These tests only cover cases of data
transmission (no connect/bind/accept etc).

Signed-off-by: Arseniy Krasnov <avkrasnov@salutedevices.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>