[POWERPC] Consolidate restore_sigmask

restore_sigmask is exactly the same on 32 and 64bit, so move it to
common code.  Also move _BLOCKABLE to signal.h to avoid defining it
multiple times.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/kernel/signal.h b/arch/powerpc/kernel/signal.h
index 1e8dfb8..4b091d8 100644
--- a/arch/powerpc/kernel/signal.h
+++ b/arch/powerpc/kernel/signal.h
@@ -10,6 +10,9 @@
 #ifndef _POWERPC_ARCH_SIGNAL_H
 #define _POWERPC_ARCH_SIGNAL_H
 
+#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
+
+extern void restore_sigmask(sigset_t *set);
 extern void check_syscall_restart(struct pt_regs *regs, struct k_sigaction *ka,
 				  int has_handler);