[PATCH] ppc64: Set ARCH_MIN_TASKALIGN

From: Benjamin Herrenschmidt <benh@kernel.crashing.org>

We need some alignement of those structs for proper operations especially
with FP and Altivec, or SLAB_DEBUG can break us.

include/asm-ppc64/processor.h

@@ -553,6 +553,8 @@ struct thread_struct {
 #endif /* CONFIG_ALTIVEC */
 };
 
+#define ARCH_MIN_TASKALIGN 16
+
 #define INIT_SP		(sizeof(init_stack) + (unsigned long) &init_stack)
 
 #define INIT_THREAD  { \