Adds support for PF_FREEZE on ppc

Hello,

While trying to use the /sys/power interface on a ppc target, I noticed that the processes didn't freeze. Apparently, since that interface was never used on ppc beforce, signal.c didn't handle the signal.

The patch below fixes that for me.

Sylvain

===== arch/ppc/kernel/signal.c 1.40 vs edited =====

@@ -24,6 +24,7 @@

#include <linux/wait.h>
#include <linux/ptrace.h>
#include <linux/unistd.h>
+#include <linux/suspend.h>
#include <linux/stddef.h>
#include <linux/elf.h>
#include <linux/tty.h>
@@ -616,6 +617,11 @@

       if (!oldset)
               oldset = &current->blocked;

+
+ if (current->flags & PF_FREEZE) {
+ refrigerator(0);
+ return 0;
+ }

       newsp = frame = 0;