tools power x86_energy_perf_policy: Override CFLAGS assignments and add LDFLAGS to build command

So user could specify outside CFLAGS/LDFLAGS values.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Herton Krzesinski <herton@redhat.com>
Cc: Len Brown <len.brown@intel.com>
Link: https://lkml.kernel.org/r/20181212102537.25902-2-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/power/x86/x86_energy_perf_policy/Makefile

@@ -9,12 +9,12 @@ ifeq ("$(origin O)", "command line")
 endif
 
 x86_energy_perf_policy : x86_energy_perf_policy.c
-CFLAGS +=	-Wall
-CFLAGS +=	-DMSRHEADER='"../../../../arch/x86/include/asm/msr-index.h"'
+override CFLAGS +=	-Wall
+override CFLAGS +=	-DMSRHEADER='"../../../../arch/x86/include/asm/msr-index.h"'
 
 %: %.c
 	@mkdir -p $(BUILD_OUTPUT)
-	$(CC) $(CFLAGS) $< -o $(BUILD_OUTPUT)/$@
+	$(CC) $(CFLAGS) $< -o $(BUILD_OUTPUT)/$@ $(LDFLAGS)
 
 .PHONY : clean
 clean :