RDMA/nldev: Expose kernel-internal FRMR pools in netlink

RDMA/nldev: Expose kernel-internal FRMR pools in netlink

Allow netlink users, through the usage of driver-details netlink
attribute, to get information about internal FRMR pools that use the
kernel_vendor_key FRMR key member.

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-v4-11-95360b54f15e@nvidia.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>