dt-bindings: qcom: geni-se: document iommus

Document the iommus property for QCOM Geni SE.
Signed-off-by: Caleb Connolly <caleb@connolly.tech>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20210408161953.26298-4-caleb@connolly.techSigned-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

Documentation/devicetree/bindings/soc/qcom/qcom,geni-se.yaml

@@ -51,6 +51,9 @@ properties:
   interconnect-names:
     const: qup-core
 
+  iommus:
+    maxItems: 1
+
 required:
   - compatible
   - reg