* Synchronize the code of the rt mart branch to the master branch.
* TTY device
* Add lwP code from rt-smart
* Add vnode in DFS, but DFS will be re-write for rt-smart
* There are three libcpu for rt-smart:
* arm/cortex-a, arm/aarch64
* riscv64
Co-authored-by: Rbb666 <zhangbingru@rt-thread.com>
Co-authored-by: zhkag <zhkag@foxmail.com>
版本控制规范：https://semver.org/
目前的版本子号不是很规范，其中RT_VERSION甚至和VS那边造成了冲突
```c
/* RT-Thread version information */
#define RT_VERSION 4L /**< major version number */
#define RT_SUBVERSION 1L /**< minor version number */
#define RT_REVISION 1L /**< revise version number */
```
参考ESP32：
```c
/** Major version number (X.x.x) */
#define ESP_ARDUINO_VERSION_MAJOR 2
/** Minor version number (x.X.x) */
#define ESP_ARDUINO_VERSION_MINOR 0
/** Patch version number (x.x.X) */
#define ESP_ARDUINO_VERSION_PATCH 3
```
建议改成：
```c
/* Major version number (X.x.x) */
#define RT_VERSION_MAJOR 4
/* Minor version number (x.X.x) */
#define RT_VERSION_MINOR 2
/* Patch version number (x.x.X) */
#define RT_VERSION_PATCH 0
```
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