[POWERPC] Add compat handler for PTRACE_GETSIGINFO

Current versions of gdb require a working implementation of
PTRACE_GETSIGINFO for proper watchpoint support.  Since struct siginfo
contains pointers it must be converted when passed to a 32-bit debugger.

Signed-off-by: Andreas Schwab <schwab@suse.de>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/kernel/ppc32.h b/arch/powerpc/kernel/ppc32.h
index 90e5627..fda05e2 100644
--- a/arch/powerpc/kernel/ppc32.h
+++ b/arch/powerpc/kernel/ppc32.h
@@ -135,4 +135,6 @@
 	struct mcontext32	uc_mcontext;
 };
 
+extern int copy_siginfo_to_user32(struct compat_siginfo __user *d, siginfo_t *s);
+
 #endif  /* _PPC64_PPC32_H */