staging/rdma/hfi1: Fetch platform configuration data from EFI variable

The platform configuration data has been moved into the EFI variable
store where it is populated by the HFI1 option ROM. This patch pulls
the configuration data from the new location, retaining a fallback to
request_firmware.

Reviewed-by: Dean Luick <dean.luick@intel.com>
Signed-off-by: Easwar Hariharan <easwar.hariharan@intel.com>
Signed-off-by: Jubin John <jubin.john@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>