staging/rdma/hfi1: use new RNR timer

Use the new RNR timer for hfi1.

For qib, this timer doesn't exist, so exploit driver
callbacks to use the new timer as appropriate.

Reviewed-by: Jubin John <jubin.john@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>