ARM: tegra: Enable PSCI support for Tegra210 and Tegra186

The PSCI nodes are currently not populated for the Tegra210 and Tegra186
devices. This prevents the PSCI driver from being able to identify the
PSCI method used by these devices and causes the probe of the PSCI
driver to fail.

Since commit 81ea0083 ("efi_loader: PSCI reset and shutdown") was
added, which moves the PSCI EFI system reset handler into the PSCI
driver, this has prevented the EFI system reset from working for
Tegra210 and Tegra186. Therefore, populating these nodes is necessary
to fix the EFI system reset for Tegra210 and Tegra186.

Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Tested-by: Peter Robinson <pbrobinson@gmail.com>