util/bucts: Clean up Makefile to match others

- Add a TARGET variable
- Enable optimization and additional warnings
- Add distclean target
- Add help target

Signed-off-by: Martin Roth <martin@coreboot.org>
Change-Id: I8eb190abd1ab20da7dd1ae43ef0358ba91df000e
Reviewed-on: https://review.coreboot.org/c/coreboot/+/50847
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>

util/bucts/Makefile

@@ -1,21 +1,32 @@
 CC:=gcc
 OBJ:=bucts.o
+TARGET=bucts
 VERSION:=$(shell git describe)
-CFLAGS+=-Wall
+WERROR=-Werror
+CFLAGS=-O2 -Wall -Wextra -Wshadow ${WERROR}
 
 ifeq ($(shell uname), FreeBSD)
 	CFLAGS += -I/usr/local/include
 	LDFLAGS += -L/usr/local/lib
 endif
 
-all: bucts
+all: $(TARGET)
 
-bucts: $(OBJ)
+$(TARGET): $(OBJ)
 	$(CC) -o $@ $(OBJ) $(LDFLAGS) -lpci
 
 %.o: %.c
 	$(CC) $(CFLAGS) -DVERSION='"$(VERSION)"' -c $<
 
-.PHONY: clean
 clean:
 	rm -f bucts $(OBJ)
+
+distclean: clean
+
+help:
+	@echo "${TARGET}: tool to manipulate the BUC.TS bit on Intel targets."
+	@echo "Targets: all, clean, distclean, help"
+	@echo "To disable warnings as errors, run make as:"
+	@echo "  make all WERROR=\"\""
+
+.PHONY: all clean distclean help