tools/thermal: tmon: use "-fstack-protector" only if supported

Most, but not all, toolchains support the "-fstack-protector" flag. We
check if the compiler supports the flag before using it. This allows
tmon to be compiled for more environments.
Signed-off-by: Markus Mayer <mmayer@broadcom.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

tools/thermal/tmon/Makefile

+# We need this for the "cc-option" macro.
+include ../../../scripts/Kbuild.include
+
 VERSION = 1.0
 
 BINDIR=usr/bin
 WARNFLAGS=-Wall -Wshadow -W -Wformat -Wimplicit-function-declaration -Wimplicit-int
-CFLAGS+= -O1 ${WARNFLAGS} -fstack-protector
+CFLAGS+= -O1 ${WARNFLAGS}
+# Add "-fstack-protector" only if toolchain supports it.
+CFLAGS+= $(call cc-option,-fstack-protector)
 CC=$(CROSS_COMPILE)gcc
 
 CFLAGS+=-D VERSION=\"$(VERSION)\"