esp8266: build system.elf by default

src/arch/esp8266/Makefile.inc

@@ -72,10 +72,6 @@ endif
 	${QUIET}${CC} ${INCLUDES} ${COMMON_FLAGS} ${CFLAGS} -c -o $@ ${@:.o=.c}
 	${QUIET}${OBJCOPY} --rename-section .text=.irom0.text --rename-section .literal=.irom0.literal $@
 
-build/system.ar: ${OBJECTS}
-	${QUIET}mkdir -p build
-	${QUIET}${AR} cru $@ ${OBJECTS}
-
 build/system.elf: build/system.ar
 	${QUIET}${CC} -L${SDK_BASE}/lib -T${SDK_BASE}/lib/eagle.app.v6-derf.ld ${LDFLAGS} \
 		-Wl,--gc-sections \
@@ -83,6 +79,10 @@ build/system.elf: build/system.ar
 		-lmain $< -Wl,--end-group -o $@
 	${QUIET}${SIZE} build/system.elf | tail -n1 | awk '{ print "  ROM: " ($$1+$$2) " (" int(($$1+$$2)*100/4194304) "%)     RAM: " ($$2 + $$3) " (" int(($$2+$$3)*100/81920) "%)" }'
 
+build/system.ar: ${OBJECTS}
+	${QUIET}mkdir -p build
+	${QUIET}${AR} cru $@ ${OBJECTS}
+
 build/0x00000.bin: build/system.elf
 	${ESPTOOL} --chip esp8266 elf2image -o build/ $<