common: Add support for Android DT image

Android documentation recommends new image format for storing DTB/DTBO
files: [1]. To support that format, this patch adds helper functions for
Android DTB/DTBO format. In image-android-dt.* files you can find helper
functions to work with Android DT image format, such us routines for:
- printing the dump of image structure
- getting the address and size of desired dtb/dtbo file

This patch uses dt_table.h file, that was added in commit 643cefa4d848
("Import Android's dt_table.h for DT image format") by Alex Deymo.

[1] https://source.android.com/devices/architecture/dto/partitions

Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
Reviewed-by: Tom Rini <trini@konsulko.com>