IB/hfi1: Move rvt_cq_wc struct into uapi directory

The rvt_cq_wc struct elements are shared between rdmavt and the providers
but not in uapi directory.  As per the comment in
https://marc.info/?l=linux-rdma&m=152296522708522&w=2

 The hfi1 driver and
the rdma core driver are not using shared structures in the uapi
directory.

In that case, move rvt_cq_wc struct into the rvt-abi.h header file and
create a rvt_k_cq_w for the kernel completion queue.

Signed-off-by: Kamenee Arumugam <kamenee.arumugam@intel.com>
Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>