arm: Tegra: Use ODMDATA from BCT in IRAM

arm: Tegra: Use ODMDATA from BCT in IRAM

Walk the BIT and BCT to find the ODMDATA word in the
CustomerData field and put it into Scratch20 reg for
use by kernel, etc.

Built all Tegra builds OK; Booted on Seaboard and saw
ODMDATA in PMC scratch20 was the same as the value in my
burn-u-boot.sh file (0x300D8011). NOTE: All flash utilities
will have to specify the odmdata (nvflash --odmdata n) on
the command line or via a cfg file, or built in to their
BCT.

Signed-off-by: Tom Warren <twarren@nvidia.com>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>