tools cpupower: Override CFLAGS assignments

So user could specify outside CFLAGS values.

Cc: Thomas Renninger <trenn@suse.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Shuah Khan (Samsung OSG) <shuah@kernel.org>

tools/power/cpupower/Makefile

@@ -129,7 +129,7 @@ WARNINGS += $(call cc-supports,-Wno-pointer-sign)
 WARNINGS += $(call cc-supports,-Wdeclaration-after-statement)
 WARNINGS += -Wshadow
 
-CFLAGS += -DVERSION=\"$(VERSION)\" -DPACKAGE=\"$(PACKAGE)\" \
+override CFLAGS += -DVERSION=\"$(VERSION)\" -DPACKAGE=\"$(PACKAGE)\" \
 		-DPACKAGE_BUGREPORT=\"$(PACKAGE_BUGREPORT)\" -D_GNU_SOURCE
 
 UTIL_OBJS =  utils/helpers/amd.o utils/helpers/msr.o \
@@ -156,12 +156,12 @@ LIB_SRC = 	lib/cpufreq.c lib/cpupower.c lib/cpuidle.c
 LIB_OBJS = 	lib/cpufreq.o lib/cpupower.o lib/cpuidle.o
 LIB_OBJS :=	$(addprefix $(OUTPUT),$(LIB_OBJS))
 
-CFLAGS +=	-pipe
+override CFLAGS +=	-pipe
 
 ifeq ($(strip $(NLS)),true)
 	INSTALL_NLS += install-gmo
 	COMPILE_NLS += create-gmo
-	CFLAGS += -DNLS
+	override CFLAGS += -DNLS
 endif
 
 ifeq ($(strip $(CPUFREQ_BENCH)),true)
@@ -175,7 +175,7 @@ ifeq ($(strip $(STATIC)),true)
         UTIL_SRC += $(LIB_SRC)
 endif
 
-CFLAGS += $(WARNINGS)
+override CFLAGS += $(WARNINGS)
 
 ifeq ($(strip $(V)),false)
 	QUIET=@
@@ -188,10 +188,10 @@ export QUIET ECHO
 
 # if DEBUG is enabled, then we do not strip or optimize
 ifeq ($(strip $(DEBUG)),true)
-	CFLAGS += -O1 -g -DDEBUG
+	override CFLAGS += -O1 -g -DDEBUG
 	STRIPCMD = /bin/true -Since_we_are_debugging
 else
-	CFLAGS += $(OPTIMIZATION) -fomit-frame-pointer
+	override CFLAGS += $(OPTIMIZATION) -fomit-frame-pointer
 	STRIPCMD = $(STRIP) -s --remove-section=.note --remove-section=.comment
 endif