staging: dpaa2-ethsw: move port notifier per ethsw

Register a different net_device notifier block per ethsw instance.
When probing multiple dpaa2-ethsw instances, without this the register
will fail.

Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Link: https://lore.kernel.org/r/1573491058-24766-2-git-send-email-ioana.ciornei@nxp.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>