Introduce maximum WQE size to impose limits on max SGE's and inline data

Link: https://lore.kernel.org/r/1578962480-17814-2-git-send-email-rao.shoaib@oracle.comSigned-off-by: Rao Shoaib <rao.shoaib@oracle.com>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>