unify default ptrace_signal_deliver

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

arch/ia64/include/asm/signal.h

@@ -38,7 +38,5 @@ struct k_sigaction {
 
 #  include <asm/sigcontext.h>
 
-#define ptrace_signal_deliver(regs, cookie) do { } while (0)
-
 # endif /* !__ASSEMBLY__ */
 #endif /* _ASM_IA64_SIGNAL_H */