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

Documentation/devicetree/bindings/iommu/rockchip,iommu.yaml

@@ -19,7 +19,9 @@ description: |+
 
 properties:
   compatible:
-    const: rockchip,iommu
+    enum:
+      - rockchip,iommu
+      - rockchip,rk3568-iommu
 
   reg:
     items:
@@ -48,6 +50,9 @@ properties:
   "#iommu-cells":
     const: 0
 
+  power-domains:
+    maxItems: 1
+
   rockchip,disable-mmu-reset:
     $ref: /schemas/types.yaml#/definitions/flag
     description: |