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.
Bao Zheng has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/54901 )

Change subject: amdfwtool: Add a function to extract firmwares
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Patch Set 10:

(2 comments)

File util/amdfwtool/extract.c:

https://review.coreboot.org/c/coreboot/+/54901/comment/4f125ac5_6228eef4 
PS6, Line 15: 0
> Use amd_fw_type enums here?

Done

https://review.coreboot.org/c/coreboot/+/54901/comment/47488f23_a9db95ad 
PS6, Line 68: psp_cookie = ppsp->header.cookie;
> Ack. Seems not good to take the filename construction out of loop.

Done.
took out of the loop.