blktests: running nvme and srp tests with real RDMA hardware

[Shinichiro Kawasaki]

Hello blktests users,

As of today, software RDMA driver "siw" or "rdma_rxe" is used to run "nvme"
group with nvme_trtype=rdma or "srp" (scsi rdma protocol) group. Now it is
suggested to run the test groups with real RDMA hardware to run tests in
more realistic conditions. A GitHub pull request is under review to support
it [1]. If you are interested in, please take a look and comment.

[1] https://github.com/osandov/blktests/pull/86