KVM: Add KVM_MMIO kconfig item

s390 doesn't have mmio, this will simplify ifdefing it out.

Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/ia64/kvm/Kconfig b/arch/ia64/kvm/Kconfig
index ef3e7be..bf82e47 100644
--- a/arch/ia64/kvm/Kconfig
+++ b/arch/ia64/kvm/Kconfig
@@ -26,6 +26,7 @@
 	select ANON_INODES
 	select HAVE_KVM_IRQCHIP
 	select KVM_APIC_ARCHITECTURE
+	select KVM_MMIO
 	---help---
 	  Support hosting fully virtualized guest machines using hardware
 	  virtualization extensions.  You will need a fairly recent