IB/{ipoib,hfi1}: Add a timeout handler for rdma_netdev

The current rdma_netdev handling in ipoib hooks the tx_timeout handler,
but prints out a totally useless message that prevents effective debugging
especially when multiple transmit queues are being used.

Add a tx_timeout rdma_netdev hook and implement the callback in the hfi1
to print additional information.

The existing non-helpful message is avoided when the driver has presented
a callback.

Link: https://lore.kernel.org/r/1617026056-50483-3-git-send-email-dennis.dalessandro@cornelisnetworks.com
Reviewed-by: Kaike Wan <kaike.wan@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>