[BSP] [NS800RT7P65]Feature/optimize ns800 uart Drive

[zhang-haitao-repo]

拉取/合并请求描述：(PR description)

[

为什么提交这份PR (why to submit this PR)

1. 为NS800RT7P65的Uart驱动新增Kconfig配置，用户可以直接通过menuconfig配置串口波特率、停止位等信息；
2. 修复NS800RT7P65Uart Drive在低波特率情况下，严重丢失报文的问题；
3. 所有提交均本地测试无问题；

你的解决方案是什么 (what is your solution)

1. Kconfig中添加波特率配置选项、Uart Drive增加波特率等相关配置的宏，覆盖默认配置；
2. 按系统 tick 等待 TX 空位，低波特率也能稳定逐字节输出

请提供验证的bsp和config (provide the config and bsp)

• BSP:

• .config:

• action:

]

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
• 如果是新增bsp, 已经添加ci检查到.github/ALL_BSP_COMPILE.json 详细请参考链接BSP自查

[github-actions]

👋 感谢您对 RT-Thread 的贡献！Thank you for your contribution to RT-Thread!

为确保代码符合 RT-Thread 的编码规范，请在你的仓库中执行以下步骤运行代码格式化工作流（如果格式化CI运行失败）。
To ensure your code complies with RT-Thread's coding style, please run the code formatting workflow by following the steps below (If the formatting of CI fails to run).

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• 将目标分支设置为 \ Set the target branch to：feature/optimize_ns800_uart_menuconfig
• 设置PR number为 \ Set the PR number to：11423

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完成后，提交将自动更新至 feature/optimize_ns800_uart_menuconfig 分支，关联的 Pull Request 也会同步更新。
Once completed, commits will be pushed to the feature/optimize_ns800_uart_menuconfig branch automatically, and the related Pull Request will be updated.

如有问题欢迎联系我们，再次感谢您的贡献！💐
If you have any questions, feel free to reach out. Thanks again for your contribution!

[Copilot]

Pull request overview

This PR adds Kconfig-based default UART configuration (baudrate / data bits / stop bits) for the ns800rt7p65-nssinepad BSP and reworks the TX wait logic in drv_uart.c to use system ticks rather than a raw loop counter, with the stated goal of preventing dropped bytes at low baudrates.

Changes:

• Add BSP_UART_DEFAULT_BAUDRATE, BSP_UART_DEFAULT_DATABITS and BSP_UART_DEFAULT_STOPBITS options to the BSP Kconfig.
• Map the new Kconfig symbols to defaults in drv_uart.c and apply them in ns800_uart_fill_default_config.
• Extract a new ns800_wait_tx_space helper that times out using rt_tick_get() / rt_tick_from_millisecond() instead of a decrementing iteration counter; ns800_putc no longer waits for the TC bit after writing.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 4 comments.

File	Description
bsp/novosns/ns800/ns800rt7p65-nssinepad/board/Kconfig	Adds default baudrate / data-bits / stop-bits menuconfig entries under the UART menu.
bsp/novosns/ns800/libraries/HAL_Drivers/drivers/drv_uart.c	Maps new Kconfig symbols to default serial_configure fields; replaces iteration-based TX timeout with a tick-based wait helper and removes the post-write TC wait in ns800_putc.