AT91: fix at91sam_wdt.c to reworked header files

Signed-off-by: Reinhard Meyer <u-boot@emk-elektronik.de>

drivers/watchdog/at91sam9_wdt.c

@@ -21,7 +21,7 @@
 #include <common.h>
 #include <watchdog.h>
 #include <asm/arch/hardware.h>
-#include <asm/arch/io.h>
+#include <asm/io.h>
 #include <asm/arch/at91_wdt.h>
 
 /*