RDMA/vmw_pvrdma: Return the correct opcode when creating WR

Since the IB_WR_REG_MR opcode value changed, let's set the PVRDMA device
opcodes explicitly.

Reported-by: Ruishuang Wang <ruishuangw@vmware.com>
Fixes: 9a59739b ("IB/rxe: Revise the ib_wr_opcode enum")
Cc: stable@vger.kernel.org
Reviewed-by: Bryan Tan <bryantan@vmware.com>
Reviewed-by: Ruishuang Wang <ruishuangw@vmware.com>
Reviewed-by: Vishnu Dasa <vdasa@vmware.com>
Signed-off-by: Adit Ranadive <aditr@vmware.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>