dt-bindings: arm-smmu: Allow mmu-400, smmu-v1 compatible

The Arm SMMUv1 DT binding only allows combining arm,mmu-401 with
arm,smmu-v1, even though the MMU-400 is compatible as well.

Allow this combination as well to let the Arm Juno board pass the test.
Signed-off-by: NAndre Przywara <andre.przywara@arm.com>
Acked-by: NRobin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/20200507112430.183940-2-andre.przywara@arm.comSigned-off-by: NWill Deacon <will@kernel.org>

Documentation/devicetree/bindings/iommu/arm,smmu.yaml

@@ -41,7 +41,9 @@ properties:
           - const: arm,mmu-500
           - const: arm,smmu-v2
       - items:
-          - const: arm,mmu-401
+          - enum:
+              - arm,mmu-400
+              - arm,mmu-401
           - const: arm,smmu-v1
       - enum:
           - arm,smmu-v1