kvm: x86: move assigned-dev.c and iommu.c to arch/x86/

Now that ia64 is gone, we can hide deprecated device assignment in x86.

Notable changes:
 - kvm_vm_ioctl_assigned_device() was moved to x86/kvm_arch_vm_ioctl()

The easy parts were removed from generic kvm code, remaining
 - kvm_iommu_(un)map_pages() would require new code to be moved
 - struct kvm_assigned_dev_kernel depends on struct kvm_irq_ack_notifier

Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

virt/kvm/kvm_main.c

@@ -2582,8 +2582,6 @@ static long kvm_vm_ioctl(struct file *filp,
 		break;
 	default:
 		r = kvm_arch_vm_ioctl(filp, ioctl, arg);
-		if (r == -ENOTTY)
-			r = kvm_vm_ioctl_assigned_device(kvm, ioctl, arg);
 	}
 out:
 	return r;