arm64: tegra: Enable SMMU translation for PCI on Tegra186

Commit 954a03be ("iommu/arm-smmu: Break insecure users by disabling
bypass by default") intentionally breaks all devices using the SMMU in
bypass mode. This breaks, among other things, PCI support on Tegra186.
Fix this by populating the iommus property and friends for the PCIe
controller.

Fixes: 954a03be ("iommu/arm-smmu: Break insecure users by disabling bypass by default")
Signed-off-by: Thierry Reding <treding@nvidia.com>