IB/hfi1: Add ioctl() interface for user commands

IOCTL is more suited to what user space commands need to do than the
write() interface. Add IOCTL definitions for all existing write commands
and the handling for those. The write() interface will be removed in a
follow on patch.

Reviewed-by: Mitko Haralanov <mitko.haralanov@intel.com>
Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>