rtc: Fix module autoload for rtc-{ab8500,max8997,s5m} drivers

These platform drivers have a platform device ID table but the module
alias information is not created so module autoloading will not work.

Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
diff --git a/drivers/rtc/rtc-max8997.c b/drivers/rtc/rtc-max8997.c
index 9e02bcd..db984d4 100644
--- a/drivers/rtc/rtc-max8997.c
+++ b/drivers/rtc/rtc-max8997.c
@@ -521,6 +521,7 @@
 	{ "max8997-rtc", 0 },
 	{},
 };
+MODULE_DEVICE_TABLE(platform, rtc_id);
 
 static struct platform_driver max8997_rtc_driver = {
 	.driver		= {