of: property: Skip adding device links to suppliers that aren't devices

of: property: Skip adding device links to suppliers that aren't devices

Some devices need to be initialized really early and can't wait for
driver core or drivers to be functional.  These devices are typically
initialized without creating a struct device for their device nodes.

If a supplier ends up being one of these devices, skip trying to add
device links to them.

Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20191028220027.251605-6-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>