staging/rdma/hfi1: Fix for 32-bit counter overflow in driver and hfi1stats

When 32-bit hardware counters overflow, hfi1stats misinterprets
the counters as being 64 bits causing the deltas for the
counters to be a huge number. This patch makes hfi1stats
aware that a counter is 32 bits by making the driver write
<counter name>,32 to debugfs.

Reviewed-by: Dean Luick <dean.luick@intel.com>
Signed-off-by: Sebastian Sanchez <sebastian.sanchez@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>