Tegra30: Add arch-tegra30 include files

Tegra30: Add arch-tegra30 include files

Common Tegra files are in arch-tegra, shared between T20 and T30.
Tegra30-specific headers are in arch-tegra30. Note that some of
these will be filled in as more T30 support is added (drivers,
WB/LP0 support, etc.). A couple of Tegra20 files were changed
to support common headers in arch-tegra, also.

Signed-off-by: Tom Warren <twarren@nvidia.com>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Simon Glass <sjg@chromium.org>