mfd: fix platform driver hotplug/coldplug

Since 43cc71eed1250755986da4c0f9898f9a635cb3bf (platform: prefix MODALIAS
with "platform:"), the platform modalias is prefixed with "platform:".
Add MODULE_ALIAS() to the MFD platform drivers, to re-enable auto loading.

[dbrownell@users.sourceforge.net: one was missing]
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Greg KH <greg@kroah.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Samuel Ortiz <samuel@sortiz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/mfd/sm501.c b/drivers/mfd/sm501.c
index 2fe6473..e2530df 100644
--- a/drivers/mfd/sm501.c
+++ b/drivers/mfd/sm501.c
@@ -1378,6 +1378,8 @@
 	.remove		= sm501_pci_remove,
 };
 
+MODULE_ALIAS("platform:sm501");
+
 static struct platform_driver sm501_plat_drv = {
 	.driver		= {
 		.name	= "sm501",