driver core: Add missing description of new struct device_link field

Commit 36003d4cf57c ("driver core: Fix PM-runtime for links added
during consumer probe") forgot to add a kerneldoc decription for the
new struct device_link member added by it, so do that now.

Fixes: 36003d4cf57c ("driver core: Fix PM-runtime for links added during consumer probe")
Reported-by: kbuild test robot <[e-mail]>
Signed-off-by: Rafael J. Wysocki <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

include/linux/device.h

···
  * @rpm_active: Whether or not the consumer device is runtime-PM-active.
  * @kref: Count repeated addition of the same link.
  * @rcu_head: An RCU head to use for deferred execution of SRCU callbacks.
+ * @supplier_preactivated: Supplier has been made active before consumer probe.
  */
 struct device_link {
 	struct device *supplier;