KVM: Avoid using CONFIG_ in userspace visible headers

Kconfig symbols are not available in userspace, and are not stripped by
headers-install.  Avoid their use by adding #defines in <asm/kvm.h> to
suit each architecture.

Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/x86/include/asm/kvm.h b/arch/x86/include/asm/kvm.h
index d2e3bf3..886c940 100644
--- a/arch/x86/include/asm/kvm.h
+++ b/arch/x86/include/asm/kvm.h
@@ -9,6 +9,13 @@
 #include <linux/types.h>
 #include <linux/ioctl.h>
 
+/* Select x86 specific features in <linux/kvm.h> */
+#define __KVM_HAVE_PIT
+#define __KVM_HAVE_IOAPIC
+#define __KVM_HAVE_DEVICE_ASSIGNMENT
+#define __KVM_HAVE_MSI
+#define __KVM_HAVE_USER_NMI
+
 /* Architectural interrupt line count. */
 #define KVM_NR_INTERRUPTS 256