[bsp][wch] revert toolchain path

Author: kaidegit

bsp/wch/risc-v/yd-ch32v307vct6/rtconfig.py

@@ -10,7 +10,7 @@
 
 if  CROSS_TOOL == 'gcc':
     PLATFORM    = 'gcc'
-    EXEC_PATH   = r'C:\Users\yekai\Documents\DevTools\wch-riscv-none-elf-gcc-8\bin'
+    EXEC_PATH   = r'/opt/MRS_Toolchain_Linux_x64_V1.90/RISC-V_Embedded_GCC/bin/'
 else:
     print('Please make sure your toolchains is GNU GCC!')
     exit(0)