修改测试寄存器的用例

tb/shinTest/gen_pkt.py

@@ -1,7 +1,7 @@
 #!/usr/bin/env python
 #encoding=utf-8
 from pyutils import *
-from testcase import environment, readregs, ebmmu, errorPkt, watchdog, broadcast, sync, base, mac
+from testcase import environment, rwregs, ebmmu, errorPkt, watchdog, broadcast, sync, base, mac
 
 if __name__ == '__main__':
     environment.gen_slv_dev_num(4)