staging/rdma/hfi1: Get port type from configuration file

The current code employs a heuristic to guess the port type.
The canonical location to identify the port type of the
designed platform is from the platform configuration data.

This patch uses the previously fetched port type from the platform
configuration and removes the now obsolete heuristic routine
and its associated defines.

Reviewed-by: Arthur Kepner <arthur.kepner@intel.com>
Signed-off-by: Easwar Hariharan <easwar.hariharan@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>