dt-bindings: clock: tegra: Add clock ID for CSI TPG clock

Tegra210 uses PLLD out internally for CSI TPG. This patch adds a clock
ID for this CSI TPG clock from PLLD.

Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>