dt-bindings: iommu: mediatek: Add mediatek,infracfg phandle

Add property "mediatek,infracfg" to let the mtk_iommu driver retrieve
a phandle to the infracfg syscon instead of performing a per-soc
compatible lookup in the entire devicetree and set it as a required
property for MT2712 and MT8173.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
Link: https://lore.kernel.org/r/20220616110830.26037-2-angelogioacchino.delregno@collabora.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

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

@@ -101,6 +101,10 @@ properties:
     items:
       - const: bclk
 
+  mediatek,infracfg:
+    $ref: /schemas/types.yaml#/definitions/phandle
+    description: The phandle to the mediatek infracfg syscon
+
   mediatek,larbs:
     $ref: /schemas/types.yaml#/definitions/phandle-array
     minItems: 1
@@ -167,6 +171,18 @@ allOf:
       required:
         - power-domains
 
+  - if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - mediatek,mt2712-m4u
+              - mediatek,mt8173-m4u
+
+    then:
+      required:
+        - mediatek,infracfg
+
   - if: # The IOMMUs don't have larbs.
       not:
         properties:
@@ -191,6 +207,7 @@ examples:
             interrupts = <GIC_SPI 139 IRQ_TYPE_LEVEL_LOW>;
             clocks = <&infracfg CLK_INFRA_M4U>;
             clock-names = "bclk";
+            mediatek,infracfg = <&infracfg>;
             mediatek,larbs = <&larb0>, <&larb1>, <&larb2>,
                              <&larb3>, <&larb4>, <&larb5>;
             #iommu-cells = <1>;