amdfwtool: Add PSP ID for combo and ISH header for A/B recovery

Nobody calls the function until combo or A/B is added, so suppress the
warning for now.

Test=Majolica (Cezanne)

Change-Id: I3082b850fb3fd2d7ae83a1c4dfd89eb7e1bd0f97
Signed-off-by: Zheng Bao <fishbaozi@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/55551
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>

util/amdfwtool/Makefile

@@ -5,7 +5,7 @@ HOSTCC ?= cc
 SRC = amdfwtool.c data_parse.c
 OBJ = $(SRC:%.c=%.o)
 TARGET = amdfwtool
-WERROR=-Werror
+WERROR=-Werror -Wno-unused-function
 CFLAGS=-O2 -Wall -Wextra -Wshadow ${WERROR}
 
 all: $(TARGET)