package/chicken: pass TARGET_CFLAGS to the build system

chicken build system expects non-standard environment variables with
compiler names and compiler options. Pass buildroot TARGET_CFLAGS in
chicken C_COMPILER_OPTIMIZATION_OPTIONS.

Fixes: http://autobuild.buildroot.net/results/ce36170d67c4702f34bee025d8a46e5269c4573e/
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/chicken/chicken.mk

@@ -16,6 +16,7 @@ CHICKEN_MAKE_OPTS = \
 	ARCH=unused \
 	C_COMPILER="$(TARGET_CC)" \
 	CXX_COMPILER="$(TARGET_CXX)" \
+	C_COMPILER_OPTIMIZATION_OPTIONS="$(TARGET_CFLAGS)" \
 	PREFIX=/usr \
 	PLATFORM=linux \
 	LIBRARIAN="$(TARGET_AR)"