KVM: Move arch dependent files to new directory arch/x86/kvm/

This paves the way for multiple architecture support.  Note that while
ioapic.c could potentially be shared with ia64, it is also moved.

Signed-off-by: Avi Kivity <avi@qumranet.com>
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index d289cfc..65b4491 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1599,4 +1599,6 @@
 
 source "crypto/Kconfig"
 
+source "arch/x86/kvm/Kconfig"
+
 source "lib/Kconfig"