tty: serdev: core: Provide missing description for 'owner'

Fixes the following W=1 kernel build warning(s):

drivers/tty/serdev/core.c: In function ‘serdev_controller_remove’:
drivers/tty/serdev/core.c:811: warning: Function parameter or member 'owner' not described in '__serdev_device_driver_register'

Cc: Rob Herring <[e-mail]>
Cc: Greg Kroah-Hartman <[e-mail]>
Cc: Jiri Slaby <[e-mail]>
Cc: [e-mail]
Signed-off-by: Lee Jones <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/tty/serdev/core.c

···
 /**
  * serdev_driver_register() - Register client driver with serdev core
  * @sdrv:	client driver to be associated with client-device.
+ * @owner:	client driver owner to set.
  *
  * This API will register the client driver with the serdev framework.
  * It is typically called from the driver's module-init function.