arm: dts: berlin2q: remove duplicated interrupt-parent

The default interrupt-parent has been set in the upper layer, apb@e80000
and apb@fc0000 for example. So if the interrupt-parent isn't changed, we
don't need to set it again. This patch removes the dumplicated
interrupt-parent settings.

Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>