sandbox: fix bloblist_finish() linker error if BLOBLIST=n

Having CONFIG_OF_EMBED=y && CONFIG_BLOBLIST=n leads to the link
error:
```
ld: /tmp/ccwtRVty.ltrans0.ltrans.o: in function `state_uninit':
arch/sandbox/cpu/state.c:508: undefined reference to `bloblist_finish'
```

Fixes: 1c52fcca72b ("sandbox: Write out bloblist when exiting")
Signed-off-by: Evgeny Bachinin <EABachinin@salutedevices.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
1 file changed