valgrind: Add fix to resolve redefinition of ptrace_peeksiginfo_args.

* Fall release of CB 2013 introduced ptrace_peeksiginfo_args linux/ptrace.h
  and sys/ptrace.h. So valgrind was getting multiple definition of this structure.
* SB-1474

Signed-off-by: Noor Ahsan <noor_ahsan@mentor.com>