mlxsw: spectrum: Add an API to configure security checks

Add an API to enable or disable security checks on a local port. It will
be used by subsequent patches when the 'BR_PORT_LOCKED' flag is toggled.

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>