Tegra: Add Nvidia seaboard build configs and seaboard directory under board/tegra2. The board specific code will be added into harmony.c and seaboard.c respectively.

Signed-off-by: Jimmy Zhang <jimmyz.nvidia@gmail.com>

BUG=none
TEST=build and boot for both harmony and seaboard.

Review URL: http://codereview.chromium.org/3457005
Patch from Jimmy Zhang <jimmyz.nvidia@gmail.com>.

Change-Id: Iba4ee8342c0034646cbd061257553a65d8171091
27 files changed