[WATCHDOG] fix watchdog/at91rm9200_wdt.c compilation

This patch fixes the following compile error:

<--  snip  -->

...
  CC      drivers/watchdog/at91rm9200_wdt.o
at91rm9200_wdt.c:188: error: 'at91_wdt_ioctl' undeclared here (not in a 
make[3]: *** [drivers/watchdog/at91rm9200_wdt.o] Error 1

<--  snip  -->
Reported-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

drivers/watchdog/at91rm9200_wdt.c

@@ -128,7 +128,7 @@ static struct watchdog_info at91_wdt_info = {
 /*
  * Handle commands from user-space.
  */
-static long at91_wdt_ioct(struct file *file,
+static long at91_wdt_ioctl(struct file *file,
 					unsigned int cmd, unsigned long arg)
 {
 	void __user *argp = (void __user *)arg;