bridge: mrp: Restore port state when deleting MRP instance

When a MRP instance is deleted, then restore the port according to the
bridge state. If the bridge is up then the ports will be in forwarding
state otherwise will be in disabled state.

Fixes: 9a9f26e8 ("bridge: mrp: Connect MRP API with the switchdev API")
Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>