Change in coreboot[master]: amdfwtool: Add a function to extract firmwares

[Bao Zheng (Code Review)]

Attention is currently required from: Jason Glenesk, Raul Rangel, Martin Roth, Marshall Dawson, Zheng Bao, Felix Held.
Hello build bot (Jenkins), Jason Glenesk, Raul Rangel, Martin Roth, Marshall Dawson, Paul Menzel, Zheng Bao, Felix Held,

I'd like you to reexamine a change. Please visit

https://review.coreboot.org/c/coreboot/+/54901

to look at the new patch set (#7).

Change subject: amdfwtool: Add a function to extract firmwares
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amdfwtool: Add a function to extract firmwares

This is one of the steps to replace the firmwares of an image.
The brief steps would be:
    o cbfstool to extract and/or remove files from the image
    o amdfwtool to regenerate the amdfw.rom image
       - extract all the firmwares in the image (* this change)
       - replace the fireware
       - regenerate the amdfw.rom
    o cbfstool to insert the new one

Change-Id: I74a6c7ff56cc11530695d1068763ecdd86282a17
Signed-off-by: Zheng Bao 
---
M util/amdfwtool/Makefile
M util/amdfwtool/Makefile.inc
M util/amdfwtool/amdfwtool.c
M util/amdfwtool/amdfwtool.h
A util/amdfwtool/extract.c
5 files changed, 287 insertions(+), 4 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/01/54901/7