ARM: tegra: Enable CPU DFLL on Nyan

Enable CPU DFLL node on Nyan Chromebooks. DFLL was previously disabled due
to Linux kernel CPUFreq driver which didn't support suspend-resume. That
problem was fixed years ago, but DFLL was never re-enabled.

Tested-by: Thomas Graichen <thomas.graichen@gmail.com> # T124 Nyan Big
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>