IB/hfi1: Remove unnecessary header

While running perftests, there is a significant utilization of the
random number daemon. This is due to the linux/random.h header being
included in qp.c and verbs.c. However, none of the functions from this
header are being used in these files, so remove the unnecessary header.

Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Jubin John <jubin.john@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>