ubus: compile with LTO enabled

Reduces total .ipk size by about 1k

Signed-off-by: Felix Fietkau <nbd@nbd.name>

package/system/ubus/Makefile

@@ -47,7 +47,8 @@ define Package/libubus-lua
   TITLE:=Lua binding for the OpenWrt RPC client
 endef
 
-TARGET_CFLAGS += -I$(STAGING_DIR)/usr/include
+TARGET_CFLAGS += -I$(STAGING_DIR)/usr/include -flto
+TARGET_LDFLAGS += -flto
 
 CMAKE_OPTIONS = \
 	-DLUAPATH=/usr/lib/lua