video: tegra: host: adding throughput hint in 3dfs

video: tegra: host: adding throughput hint in 3dfs

adding support for using a throughput hint given by the tegra-gfx misc
device in the 3d scaling code. If throughput hint usage is enabled and
the latest throughput hint is recent enough (less than 1 second old),
the throughput hint is used to control 3d frequency scaling. Otherwise
the existing idle time percentage estimate is used.

Bug 991589

Change-Id: I68893e5ce7ef922b95ce5f5b3664eb8e1fdd4027
Signed-off-by: Ilan Aelion <iaelion@nvidia.com>
Reviewed-on: http://git-master/r/116866
Reviewed-by: Lokesh Pathak <lpathak@nvidia.com>
Tested-by: Lokesh Pathak <lpathak@nvidia.com>