dpaa2-eth: add irq for the dpmac connect/disconnect event

Add IRQ for the DPNI endpoint change event, resolving the issue
when a dynamically created DPNI gets a randomly generated hw address
when the endpoint is a DPMAC object.

Signed-off-by: Florin Chiculita <florinlaurentiu.chiculita@nxp.com>
Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>