Clear breakpoints so that gdb will not single step

Signed-off-by: liangzhen <[email protected]>
Change-Id: I7a4a24972cfa2ddc307a5f06fe3fd5380794719f

Author: lz-bro

debug/gdbserver.py

@@ -2139,6 +2139,7 @@ def test(self):
         main_post_csrr = self.gdb.p("&main_post_csrr")
         assertEqual(self.gdb.p("$pc"), main_post_csrr)
 
+        self.gdb.command("delete")
         self.gdb.command("monitor riscv icount clear")
 
         # Execute 1 instruction.