Documentation: Add binary extraction documentation

Added documentation on how to extract binaries from a ROM image,
including:

- Using ifdtool to extract binaries.
- Using cbfstool to extract binaries.
- Changing menuconfig to use the extracted binaries.

Change-Id: Ia31b01afc66789f95c7d21a0d41b532bc19a6430
Signed-off-by: Logan Carlson <logancarlson@google.com>
Reviewed-on: https://review.coreboot.org/20753
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Martin Roth <martinroth@google.com>
1 file changed