KVM: PPC: Put segment registers in shared page

Now that the actual mtsr doesn't do anything anymore, we can move the sr
contents over to the shared page, so a guest can directly read and write
its sr contents from guest context.

Signed-off-by: Alexander Graf <agraf@suse.de>
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index 496d7a5..028891c 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -66,7 +66,7 @@
 		vcpu->arch.magic_page_pa = param1;
 		vcpu->arch.magic_page_ea = param2;
 
-		r2 = 0;
+		r2 = KVM_MAGIC_FEAT_SR;
 
 		r = HC_EV_SUCCESS;
 		break;