[ch32v307] 删掉无意义的memset重载 (#6561)

bsp/wch/risc-v/ch32v307v-r1/rtconfig.py

@@ -47,7 +47,6 @@ if PLATFORM == 'gcc':
     LFLAGS = DEVICE
     LFLAGS += ' -Wl,--gc-sections,-cref,-Map=' + MAP_FILE
     LFLAGS += ' -T ' + LINK_FILE
-    LFLAGS += ' -Wl,-wrap=memset'
 
     CPATH = ''
     LPATH = ''