IB/hfi1: Access hfi1_ibport through rcd pointer

Receive code paths use the QP's device and port
number to access the struct hfi1_ibport. When an
instance of struct hfi1_ctxtdata is present, it can
be used to access struct hfi1_ibport through a pointer.
This makes struct hfi1_ibport lookup time faster as an
array doesn't have to be indexed and access fields in
other cache-lines.

Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Sebastian Sanchez <sebastian.sanchez@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>