dt-bindings: arm-smmu: add binding for Tegra194 SMMU

Add binding for NVIDIA's Tegra194 SoC SMMU.

Signed-off-by: Krishna Reddy <vdumpa@nvidia.com>
Reviewed-by: Jon Hunter <jonathanh@nvidia.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/20200718193457.30046-5-vdumpa@nvidia.com
Signed-off-by: Will Deacon <will@kernel.org>