ARM: tegra: Populate OPP table for Tegra20 Ventana

Commit 9ce27463 ("cpufreq: tegra20: Use generic cpufreq-dt driver
(Tegra30 supported now)") update the Tegra20 CPUFREQ driver to use the
generic CPUFREQ device-tree driver. Since this change CPUFREQ support
on the Tegra20 Ventana platform has been broken because the necessary
device-tree nodes with the operating point information are not populated
for this platform. Fix this by updating device-tree for Venata to
include the operating point informration for Tegra20.

Fixes: 9ce27463 ("cpufreq: tegra20: Use generic cpufreq-dt driver (Tegra30 supported now)")
Cc: stable@vger.kernel.org
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>