dt-bindings: interrupt-controller/uniphier-aidet: Add bindings for NX1 SoC

Update uniphier-aidet binding document for UniPhier NX1 SoC.

Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/1653023822-19229-2-git-send-email-hayashi.kunihiko@socionext.com