watchdog: sp5100: Fix definition of EFCH_PM_DECODEEN3

EFCH_PM_DECODEEN3 is supposed to access DECODEEN register bits 24..31,
in other words the register at byte offset 3.

Cc: Jan Kiszka <jan.kiszka@siemens.com>
Fixes: 887d2ec5 ("watchdog: sp5100_tco: Add support for recent FCH versions")
Tested-by: Jan Kiszka <jan.kiszka@siemens.com>
Link: https://lore.kernel.org/r/20200910163109.235136-1-linux@roeck-us.netSigned-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

drivers/watchdog/sp5100_tco.h

@@ -70,7 +70,7 @@
 #define EFCH_PM_DECODEEN_WDT_TMREN	BIT(7)
 
 
-#define EFCH_PM_DECODEEN3		0x00
+#define EFCH_PM_DECODEEN3		0x03
 #define EFCH_PM_DECODEEN_SECOND_RES	GENMASK(1, 0)
 #define EFCH_PM_WATCHDOG_DISABLE	((u8)GENMASK(3, 2))