RDMA/hw/i40iw/i40iw_hw: Provide description for 'ipv4', remove 'user_pri' and fix 'iwcq'

Fixes the following W=1 kernel build warning(s):

 drivers/infiniband/hw/i40iw/i40iw_hw.c:172: warning: Function parameter or member 'iwcq' not described in 'i40iw_iwarp_ce_handler'
 drivers/infiniband/hw/i40iw/i40iw_hw.c:172: warning: Excess function parameter 'iwcp' description in 'i40iw_iwarp_ce_handler'
 drivers/infiniband/hw/i40iw/i40iw_hw.c:529: warning: Function parameter or member 'ipv4' not described in 'i40iw_manage_arp_cache'
 drivers/infiniband/hw/i40iw/i40iw_hw.c:592: warning: Excess function parameter 'user_pri' description in 'i40iw_manage_qhash'

Link: https://lore.kernel.org/r/20210118223929.512175-7-lee.jones@linaro.org
Cc: Faisal Latif <faisal.latif@intel.com>
Cc: Shiraz Saleem <shiraz.saleem@intel.com>
Cc: Doug Ledford <dledford@redhat.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: linux-rdma@vger.kernel.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>