RDMA/irdma: Make the source udp port vary

Get the source udp port number for a QP based on the grh.flow_label or
lqpn/rqrpn. This provides a better spread of traffic across NIC RX queues.

Link: https://lore.kernel.org/r/20220106180359.2915060-4-yanjun.zhu@linux.dev


Signed-off-by: Zhu Yanjun <yanjun.zhu@linux.dev>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Acked-by: Shiraz Saleem <shiraz.saleem@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>