ARM64: tegra: Add chosen node for tegra132 norrin

The NVIDIA bootloader, nvtboot, expects the "chosen" node to be present
in the device-tree blob and if it is not then it fails to boot the kernel.
Add the chosen node so we can boot the kernel on Tegra132 Norrin with the
nvtboot bootloader.

Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Olof Johansson <olof@lixom.net>