[BSP] reduce the code size for STM32F0x

bsp/stm32f0x/rtconfig.h

@@ -83,11 +83,13 @@
 #define FINSH_THREAD_STACK_SIZE	1024
 #define FINSH_HISTORY_LINES	1
 /* Using symbol table */
-#define FINSH_USING_SYMTAB
-#define FINSH_USING_DESCRIPTION
+//#define FINSH_USING_SYMTAB
+//#define FINSH_USING_DESCRIPTION
+#define FINSH_USING_MSH
+#define FINSH_USING_MSH_ONLY
 
 /* SECTION: libc management */
-#define RT_USING_LIBC
+// #define RT_USING_LIBC
 
 /* SECTION: device filesystem */
 /* #define RT_USING_DFS */