virtio_pci: drop Kconfig warnings

The ABI *is* stable, and has been for a while now.
Drop Kconfig warning saying that it's not guaranteed
to work.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

drivers/virtio/Kconfig

@@ -17,9 +17,6 @@ config VIRTIO_PCI
 	  virtio backends.  Most QEMU based VMMs should support these devices
 	  (like KVM or Xen).
 
-	  Currently, the ABI is not considered stable so there is no guarantee
-	  that this version of the driver will work with your VMM.
-
 	  If unsure, say M.
 
 config VIRTIO_BALLOON