powerpc: Fix 64-bit hibernation with 64k pages

A bug in my initial 64-bit hibernation code breaks it when using
page sizes that aren't 4K.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/kernel/swsusp_asm64.S

@@ -133,7 +133,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
 
 	cmpdi	r12,0
 	beq-	nothing_to_copy
-	li	r15,512
+	li	r15,PAGE_SIZE>>3
 copyloop:
 	ld	r13,pbe_address(r12)
 	ld	r14,pbe_orig_address(r12)