[XS] Change in coreboot[main]: amdfwtool: make fields unsigned

[George Burgess (Code Review)]

Attention is currently required from: Felix Held, Fred Reitberger, George Burgess, Martin L Roth, Matt DeVillier.

Hello Felix Held, Fred Reitberger, Martin L Roth, Matt DeVillier, build bot (Jenkins),

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

https://review.coreboot.org/c/coreboot/+/83412?usp=email

to look at the new patch set (#2).

The following approvals got outdated and were removed:
Verified+1 by build bot (Jenkins)

Change subject: amdfwtool: make fields unsigned
......................................................................

amdfwtool: make fields unsigned

The value stored in `gen` is only ever `1` or `0`. Storing `1` causes
Clang to warn, since the only valid values for a 1-bit int are -1 and 0:
```
amdfwtool.c:1487:27: error: implicit truncation from 'int' to a one-bit
wide bit-field changes value from 1 to -1
[-Werror,-Wsingle-bit-bitfield-constant-conversion]
 1487 |                 amd_romsig->efs_gen.gen = EFS_BEFORE_SECOND_GEN;
```

TEST=Rebuilt coreboot; no warning was emitted.

Change-Id: Ibd83be8302e8a717db7e7dc86a403b5648976586
Signed-off-by: George Burgess IV 
---
M util/amdfwtool/amdfwtool.h
1 file changed, 2 insertions(+), 2 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/12/83412/2