IB/hfi1: Setup common IB fields in hfi1_packet struct

We move many common IB fields into the hfi1_packet structure and
set them up in a single function. This allows us to set the fields
in a single place and not deal with them throughout the driver.

Reviewed-by: Brian Welty <brian.welty@intel.com>
Reviewed-by: Dasaratharaman Chandramouli <dasaratharaman.chandramouli@intel.com>
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Don Hiatt <don.hiatt@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>