tegra20: rename tegra2 -> tegra20

This is make naming consistent with the kernel and devicetree and in
preparation of pulling out the common tegra20 code.

Signed-off-by: Allen Martin <amartin@nvidia.com>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Tested-by: Thierry Reding <thierry.reding@avionic-design.de>
Signed-off-by: Tom Warren <twarren@nvidia.com>
85 files changed