platform: Document platform_add_devices() return value

platform_add_devices() returns 0 on success and negative
errno on failure. Document it.
Signed-off-by: Umang Jain <umang.jain@ideasonboard.com>
Link: https://lore.kernel.org/r/20221220085116.19837-1-umang.jain@ideasonboard.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/base/platform.c

@@ -499,6 +499,8 @@ EXPORT_SYMBOL_GPL(platform_get_irq_byname_optional);
  * platform_add_devices - add a numbers of platform devices
  * @devs: array of platform devices to add
  * @num: number of platform devices in array
+ *
+ * Return: 0 on success, negative error number on failure.
  */
 int platform_add_devices(struct platform_device **devs, int num)
 {