watchdog: bcm2835_wdt: Fix module autoload

The commit 5e6acc3e ("bcm2835-pm: Move bcm2835-watchdog's DT probe
to an MFD.") broke module autoloading on Raspberry Pi. So add a
module alias this fix this.
Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

drivers/watchdog/bcm2835_wdt.c

@@ -238,6 +238,7 @@ module_param(nowayout, bool, 0);
 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
 				__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
 
+MODULE_ALIAS("platform:bcm2835-wdt");
 MODULE_AUTHOR("Lubomir Rintel <lkundrak@v3.sk>");
 MODULE_DESCRIPTION("Driver for Broadcom BCM2835 watchdog timer");
 MODULE_LICENSE("GPL");