ARM: dts: rockchip: add interrupt for Wake-on-Lan on RK3288

In order to use Wake-on-Lan on RK3288 integrated MAC, we need to wake-up
the CPU on the PMT interrupt when the MAC and the PHY are in low power mode.
Adding the interrupt declaration.

Signed-off-by: Vincent Palatin <vpalatin@chromium.org>
Signed-off-by: David S. Miller <davem@davemloft.net>