[serial]: 增加超时事件处理

[meng-plus]

拉取/合并请求描述：(PR description)

[

为什么提交这份PR (why to submit this PR)

#8143

你的解决方案是什么 (what is your solution)

完善rt_hw_serial_isr的事件分支

在什么测试环境下测试通过 (what is the test environment)

lpc4088 iar8_40 个人项目中测试通过
]

当前拉取/合并请求的状态 Intent for your PR

必须选择一项 Choose one (Mandatory):

• 本拉取/合并请求是一个草稿版本 This PR is for a code-review and is intended to get feedback
• 本拉取/合并请求是一个成熟版本 This PR is mature, and ready to be integrated into the repo

代码质量 Code Quality：

我在这个拉取/合并请求中已经考虑了 As part of this pull request, I've considered the following:

• 已经仔细查看过代码改动的对比 Already check the difference between PR and old code
• 代码风格正确，包括缩进空格，命名及其他风格 Style guide is adhered to, including spacing, naming and other styles
• 没有垃圾代码，代码尽量精简，不包含#if 0代码，不包含已经被注释了的代码 All redundant code is removed and cleaned up
• 所有变更均有原因及合理的，并且不会影响到其他软件组件代码或BSP All modifications are justified and not affect other components or BSP
• 对难懂代码均提供对应的注释 I've commented appropriately where code is tricky
• 代码是高质量的 Code in this PR is of high quality
• 已经使用formatting 等源码格式化工具确保格式符合RT-Thread代码规范 This PR complies with RT-Thread code specification

[meng-plus]

使用演示

static rt_err_t finsh_rx_ind(rt_device_t dev, rt_size_t size)
{
    rt_serial_t *serial = (rt_serial_t *)dev;
    if (dev != thread_dts.device)
    {
        return RT_EOK;
    }
    if (serial->event == RT_SERIAL_EVENT_RX_TIMEOUT)
    {
        if (dev->user_data == &thread_dts)
        {
            /* release semaphore to let finsh thread rx data */
            rt_sem_release(&thread_dts.rx_sem);
        }
    }
    return RT_EOK;
}


/*thread 超时等待*/
    if (RT_EOK != rt_sem_take(&thread_dts.rx_sem, 10000)) // RT_WAITING_FOREVER
    {
        continue;
    }
    uint16_t length = rt_device_read(thread_dts.device, -1, ctx->read_buf, ctx->read_bufsz);
    rt_device_write(thread_dts.device, 0, ctx->read_buf, length);
   LOG_D("%d-> %s", length, ctx->read_buf);

感觉缺少一个接收多少串口数据的读取接口，使用回调finsh_rx_ind(rt_device_t dev, rt_size_t size)有size返回，但是这里是中断不太方便做太多操作