platform: tegra21: Support cpufreq table from DT

platform: tegra21: Support cpufreq table from DT

Added Tegra21 cpufreq driver support for parsing T210 CPU scaling data
compatible with DT binding defined in nvidia,cpufreq-tegra.txt, and
initialized cpufreq scaling table accordingly.

Bug 200085579

Change-Id: I609a9b4143e7b3df3422d4be0d5c2cd7eb4ba64a
Signed-off-by: Alex Frid <afrid@nvidia.com>
Reviewed-on: http://git-master/r/749066
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: Sai Gurrappadi <sgurrappadi@nvidia.com>
Reviewed-by: Bo Yan <byan@nvidia.com>