Adding steering infrastructure for adding and removing optional counter.
This allows to add and remove the counters dynamically in order not to
hurt performance.

Link: https://lore.kernel.org/r/20211008122439.166063-12-markzhang@nvidia.comSigned-off-by: Aharon Landau <aharonl@nvidia.com>
Reviewed-by: Maor Gottlieb <maorg@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Mark Zhang <markzhang@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>