KVM: PPC: Enable napping only for Book3s_64

Before I incorrectly enabled napping also for BookE, which would result in
needless dcache flushes. Since we only need to force enable napping on
Book3s_64 because it doesn't go into MSR_POW otherwise, we can just #ifdef
that code to this particular platform.
Reported-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>

arch/powerpc/kernel/kvm.c

@@ -582,8 +582,10 @@ static int __init kvm_guest_init(void)
 	if (kvm_para_has_feature(KVM_FEATURE_MAGIC_PAGE))
 		kvm_use_magic_page();
 
+#ifdef CONFIG_PPC_BOOK3S_64
 	/* Enable napping */
 	powersave_nap = 1;
+#endif
 
 free_tmp:
 	kvm_free_tmp();