RDMA/rxe: Delete deprecated module parameters interface

Starting from the commit 66920e1b ("rdma_rxe: Use netlink messages
to add/delete links") from the 2019, the RXE modules parameters are marked
as deprecated in favour of rdmatool. So remove the kernel code too.

Link: https://lore.kernel.org/r/c8376d7517aebe7cc851f0baaeef7b13707cf767.1641372460.git.leonro@nvidia.com


Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Reviewed-by: Zhu Yanjun <zyjzyj2000@gmail.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>