A third interrupt cell can be provided to optionally specify
the interrupt used for handling Wake on LAN events.

Typically the wake up handling uses a separate interrupt
controller, so the interrupts-extended property is used to
accommodate this.
Signed-off-by: NDoug Berger <opendmb@gmail.com>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>