dt-bindings: Update headers for Tegra234

Add a few more clocks that will be used in follow-up patches to enable
more functionality on Tegra234.

Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>