arm64: tegra: Add CPU and PSCI nodes for NVIDIA Tegra210 platforms

Add the CPU and PSCI nodes for the NVIDIA Tegra210 platforms so that
all CPUs can be enabled on boot. This assumes that the PSCI firmware
has been loaded during the initial bootstrap on the device before the
kernel starts (which is typically the case for these platforms). The
PSCI firmware version is set to v0.2 which aligns with the current
shipping version for Tegra.

Reported-by: Martin Michlmayr <tbm@cyrius.com>
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Tested-By: Vagrant Cascadian <vagrant@debian.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>