KVM: x86: mark legacy PCI device assignment as deprecated

Follow up to commit e194bbdf362ba7d53cfd23ba24f1a7c90ef69a74.

Suggested-by: Bandan Das <bsd@redhat.com>
Suggested-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/arch/x86/kvm/Kconfig b/arch/x86/kvm/Kconfig
index a0f06a5..d8a1d56 100644
--- a/arch/x86/kvm/Kconfig
+++ b/arch/x86/kvm/Kconfig
@@ -86,7 +86,7 @@
 	 auditing of KVM MMU events at runtime.
 
 config KVM_DEVICE_ASSIGNMENT
-	bool "KVM legacy PCI device assignment support"
+	bool "KVM legacy PCI device assignment support (DEPRECATED)"
 	depends on KVM && PCI && IOMMU_API
 	default n
 	---help---