watchdog: kempld_wdt: Fix bit mask definition

STAGE_CFG bits are defined as [5:4] bits. However, '(((x) & 0x30) << 4)'
handles [9:8] bits. Thus, it should be fixed in order to handle
[5:4] bits.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
diff --git a/drivers/watchdog/kempld_wdt.c b/drivers/watchdog/kempld_wdt.c
index 491419e..5c3d4df 100644
--- a/drivers/watchdog/kempld_wdt.c
+++ b/drivers/watchdog/kempld_wdt.c
@@ -35,7 +35,7 @@
 #define KEMPLD_WDT_STAGE_TIMEOUT(x)	(0x1b + (x) * 4)
 #define KEMPLD_WDT_STAGE_CFG(x)		(0x18 + (x))
 #define STAGE_CFG_GET_PRESCALER(x)	(((x) & 0x30) >> 4)
-#define STAGE_CFG_SET_PRESCALER(x)	(((x) & 0x30) << 4)
+#define STAGE_CFG_SET_PRESCALER(x)	(((x) & 0x3) << 4)
 #define STAGE_CFG_PRESCALER_MASK	0x30
 #define STAGE_CFG_ACTION_MASK		0x7
 #define STAGE_CFG_ASSERT		(1 << 3)