use __ARMCC_VERSION to replace __CC_ARM

* [rtdef] rename RT_WEAK attribute as rt_weak

* [rtdef] rename RT_USED attribute as rt_used

* [rtdef] rename RT_SECTION attribute as rt_section

* [rtdef] rename ALIGN attribute as rt_align

* [legacy] add RT_USED ALIGN RT_SECTION RT_WEAK as legacy support

如果打印格式为"%02X"的数据大于0x7F,打印的数据就会在前面多出6个'F',原因详见https://blog.csdn.net/zqxwce821/article/details/53011925。
现在通过强制转换成unsigned char后，在STM32（KEIL5+C99）已测试确认能修复该问题。

Revert "fix the bug that rx_notice out of sync when data received after last rt_device_read() is zero"

fix at_client, avoid creating the same client repeatedly and prevent working exceptions and memory leaks.

Signed-off-by: RGW <rgw5267@gmail.com>

Signed-off-by: chenyong <1521761801@qq.com>

- AT Socket feature supports multi-client connections;
- Fix `send data error, current socket (0) state (0) is error` issue when the socket is closed;
- Improve dirty data processing when AT device hard reset;
- Improve `at_obj_set_urc_table()` fucntion, Support for setting multiple URC tables;
- Improve RAW data print format;

Signed-off-by: chenyong <1521761801@qq.com>

correct a spelling mistake

修复LOG_X修改引起的编译错误