Import Android's dt_table.h for DT image format

Android documentation defines the recommended image format for storing
DTB/DTBO files in a single dtbo.img image. This patch includes the
latest header file with the struct definitions for this format from
AOSP.

The header was adapted to U-Boot's coding style and the function
declarations were removed.

Signed-off-by: Alex Deymo <deymo@google.com>
[trini: Change SDPX tag location]
Signed-off-by: Tom Rini <trini@konsulko.com>