staging/rdma/hfi1: Remove user context allocation and de-alloction functions

IB user context alloc and dealloc functions have been added to rdmavt.
This patch removes them from hfi1.

Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Harish Chegondi <harish.chegondi@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>