ARM: tegra: add seaboard, wario and kaen boards

This adds board support for the Seaboard eval platform and some of the
derivatives that are very similar. Since they only differ in some very
minor ways, most of the code is shared.

Signed-off-by: Olof Johansson <olof@lixom.net>
Acked-by: Colin Cross <ccross@android.com>