修复字符串比较错误

* [pwm]Improve the code

* 将与bsp无关的代码移植到框架部分

* 添加注释

UART_FLAG_TC 不能在中断里CLEAR;
因为函数 static int stm32_putc(struct rt_serial_device *serial, char c)里发送完成后
while 循环等这个标志退出，中断服务函数CLEAR后，此处进入死循环

* Add CANFD support and correct typos

- Added CANFD required fields to can.h
- Fixed typos in can.h and can.c
- Corrected all the projects affected by the typo
- Fixed wrong line-ending in some affected can driver files
Signed-off-by: NFan YANG <fan.yang@hpmicro.com>

* update
Signed-off-by: NFan YANG <fan.yang@hpmicro.com>
Co-authored-by: Meco Man <920369182@qq.com>

https://github.com/RT-Thread/rt-thread/issues/6106
https://github.com/RT-Thread/rt-thread/issues/4467#issuecomment-850814143

* Fix some compilation warning

* 补充修正一些数据类型的使用错误
Co-authored-by: Meco Man <920369182@qq.com>

* [bsp][stm32] f407-robomaster-c板, 添加stm32定时器8pwm默认配置

* tab -> space

* 取消DFS选定
Co-authored-by: Meco Man <920369182@qq.com>

* Fix the bug of complementary output

防止后续维护出现没有全面修改的问题

* [rt_drv_pwm]增加API：增加单独设置PWM频率和脉宽的函数

* [bsp/stm32]优化功能(drv_pwm)：设置PWM频率和脉宽时不破坏上一个PWM周期

* [stm32][soft spi] implement soft spi

用户自己可以添加DMA分配文件，所以这里的DMA分配有可能和用户自定义的冲突

[bsp][stm32][drv_adc.c]: change the bsp name of 100ask to be consistent with other bsp and commit a bug for drv_adc,c (#6068)

* [bsp][stm32][drv_adc.c]: change the bsp name of 100ask to be consistent with other bsp and commit a bug for drv_adc,c (#6068)

* [stm32] move CMSIS hearder files to common folder

* add CMSIS new sconscript

* 1. 在AT32的BSP的drv_gpio中增加了at32_pin_get函数，用于实现rt_pin_ops对象中的pin_get
2. 在MSH中增加了PIN的操作命令
3. 为了方便在MSH命令中解析字符串，增加了一些字符串相关的函数

* add adc_get_vref

add stm32_adc_get_vref

* [STM32][RTC] add support for STM32L0 series.

* Update drv_rtc.c

在串口不关闭的情况下，更改波特率后，清空上次数据检索，导致更新写入检索错误，
串口无法读出正确的数据。真实数据的位置和检索值之间总有一定的距离，导致读取
数据的时候会有一定的延时。缓冲区大，延时越长

* [stm32f401-nucleo] arduino support
* 增加application arduino main文件
* 调整目录结构

删除多余注释，另外确定了对于其他型号单片机的适应性