RDMA/core: Remove FMR device ops

After removing FMR support from all the RDMA ULPs and providers, there
is no need to keep FMR operation for IB devices.

Link: https://lore.kernel.org/r/11-v3-f58e6669d5d3+2cf-fmr_removal_jgg@mellanox.com


Signed-off-by: Max Gurtovoy <maxg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>