ARM: tegra: add DT files for Tegra124 and Venice2

These are fairly complete, and near-clones of Tegra114 Venice, with an
additional I2C port, and MMC address changes for Tegra124.

Signed-off-by: Tom Warren <twarren@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Tom Warren <twarren@nvidia.com>