KVM: PPC: Expose SYNC cap based on mmu notifiers

Semantically, the "SYNC" cap means that we have mmu notifiers available.
Express this in our #ifdef'ery around the feature, so that we can be sure
we don't miss out on ppc targets when they get their implementation.
Signed-off-by: Alexander Graf <agraf@suse.de>

arch/powerpc/kvm/powerpc.c

@@ -264,10 +264,16 @@ int kvm_dev_ioctl_check_extension(long ext)
 		if (cpu_has_feature(CPU_FTR_ARCH_201))
 			r = 2;
 		break;
+#endif
 	case KVM_CAP_SYNC_MMU:
+#ifdef CONFIG_KVM_BOOK3S_64_HV
 		r = cpu_has_feature(CPU_FTR_ARCH_206) ? 1 : 0;
-		break;
+#elif defined(KVM_ARCH_WANT_MMU_NOTIFIER)
+		r = 1;
+#else
+		r = 0;
 #endif
+		break;
 	case KVM_CAP_NR_VCPUS:
 		/*
 		 * Recommending a number of CPUs is somewhat arbitrary; we