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: Andre Przywara <andre.przywara@arm.com>
Acked-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/20200507112430.183940-2-andre.przywara@arm.com


Signed-off-by: Will Deacon <will@kernel.org>