update bsp/bl602/README.md.

Signed-off-by: 李昂 <liang6516@outlook.com>

bsp/bl602/README.md

@@ -9,7 +9,7 @@
 2. Install SDK:
     > https://blog.csdn.net/Boantong_/article/details/125604649?ops_request_misc=%257B%2522request%255Fid%2522%253A%2522166617877716800182741996%2522%252C%2522scm%2522%253A%252220140713.130102334.pc%255Fblog.%2522%257D&request_id=166617877716800182741996&biz_id=0&utm_medium=distribute.pc_search_result.none-task-blog-2~blog~first_rank_ecpm_v1~rank_v31_ecpm-3-125604649-null-null.nonecase&utm_term=wb2&spm=1018.2226.3001.4450
 
-3. 
+3. Move this bsp to SDK folder and make.
 
 ``` bash
 mv pikascript_bl602 Ai-Thinker-Wb2/