Input: axp20x-pek - add module alias

Add a proper module alias so the driver can be autoloaded when the
parent axp20x mfd driver registers its cells.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Carlo Caione <carlo@caione.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/misc/axp20x-pek.c

@@ -292,3 +292,4 @@ module_platform_driver(axp20x_pek_driver);
 MODULE_DESCRIPTION("axp20x Power Button");
 MODULE_AUTHOR("Carlo Caione <carlo@caione.org>");
 MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:axp20x-pek");