RDMA/core: Add netlink command to modify FRMR aging

RDMA/core: Add netlink command to modify FRMR aging

Allow users to set FRMR pools aging timer through netlink.
This functionality will allow user to control how long handles reside in
the kernel before being destroyed, thus being able to tune the tradeoff
between memory and HW object consumption and memory registration
optimization.
Since FRMR pools is highly beneficial for application restart scenarios,
this command allows users to modify the aging timer to their application
restart time, making sure the FRMR handles deregistered on application
teardown are kept for long enough in the pools for reuse in the
application startup.

Signed-off-by: Michael Guralnik <michaelgur@nvidia.com>
Reviewed-by: Patrisious Haddad <phaddad@nvidia.com>
Signed-off-by: Edward Srouji <edwards@nvidia.com>
Link: https://patch.msgid.link/20260226-frmr_pools-v4-9-95360b54f15e@nvidia.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>