dt-bindings: iommu: rockchip: Add compatible for v2

Add compatible for the second version of IOMMU hardware block.
RK356x IOMMU can also be link to a power domain.

Signed-off-by: Benjamin Gaignard <benjamin.gaignard@collabora.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Link: https://lore.kernel.org/r/20210604164441.798362-3-benjamin.gaignard@collabora.com


Signed-off-by: Joerg Roedel <jroedel@suse.de>