[ch32v3] 修改RT_USING为BSP_USING (#6482)
[ch32v3] 修改RT_USING为BSP_USING (#6482)

* 修改RT_USING为BSP_USING

* Update SConscript

* Update SConscript

Co-authored-by: Man, Jianting (Meco) <0fc0d424b3d1e2f837d33f3ac71f4dcb4750771e@qq.com>
RT-Thread/rt-thread,RT-Thread/rt-thread,RT-Thread/rt-thread,RT-Thread/rt-thread,RT-Thread/rt-thread,RT-Thread/rt-thread,RT-Thread/rt-thread