IB/hfi1: Support ib_alloc_mr verb

Ported from upstream qib commit
68c02e232b8a ("qib: Support ib_alloc_mr verb")

Tested-by: Jubin John <jubin.john@intel.com>
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>