powerpc: provide ppc_md.panic() for both ppc32 & ppc64

Allow boards to provide a panic callback on ppc32.  Moved the code to sets
this up into setup-common.c so its shared between ppc32 & ppc64.  Also moved
do_init_bootmem prototype into setup.h.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index 4467c49..ab6ea37 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -100,12 +100,6 @@
 #endif /* CONFIG_MAGIC_SYSRQ */
 
 
-static int ppc64_panic_event(struct notifier_block *, unsigned long, void *);
-static struct notifier_block ppc64_panic_block = {
-	.notifier_call = ppc64_panic_event,
-	.priority = INT_MIN /* may not return; must be done last */
-};
-
 #ifdef CONFIG_SMP
 
 static int smt_enabled_cmdline;
@@ -456,13 +450,6 @@
 	DBG(" <- setup_system()\n");
 }
 
-static int ppc64_panic_event(struct notifier_block *this,
-                             unsigned long event, void *ptr)
-{
-	ppc_md.panic((char *)ptr);  /* May not return */
-	return NOTIFY_DONE;
-}
-
 #ifdef CONFIG_IRQSTACKS
 static void __init irqstack_early_init(void)
 {
@@ -517,8 +504,6 @@
  */
 void __init setup_arch(char **cmdline_p)
 {
-	extern void do_init_bootmem(void);
-
 	ppc64_boot_msg(0x12, "Setup Arch");
 
 	*cmdline_p = cmd_line;
@@ -535,8 +520,7 @@
 	panic_timeout = 180;
 
 	if (ppc_md.panic)
-		atomic_notifier_chain_register(&panic_notifier_list,
-				&ppc64_panic_block);
+		setup_panic();
 
 	init_mm.start_code = PAGE_OFFSET;
 	init_mm.end_code = (unsigned long) _etext;