Fix watchdog POST for lwmon5

If the hardware watchdog detects a voltage error, the watchdog sets
GPIO62 to low. The watchdog POST has to detect this low level.

Signed-off-by: Sascha Laue <leglas0@legpc180.leg.liebherr.i>
Signed-off-by: Wolfgang Denk <wd@denx.de>

post/board/lwmon5/watchdog.c

@@ -52,8 +52,9 @@ static void watchdog_magic_write(uint value)
 
 int sysmon1_post_test(int flags)
 {
-	if (gpio_read_in_bit(CFG_GPIO_SYSMON_STATUS)) {
-		/* 3.1. GPIO62 is low
+	if (gpio_read_in_bit(CFG_GPIO_SYSMON_STATUS) == 0) {
+		/*
+		 * 3.1. GPIO62 is low
 		 * Assuming system voltage failure.
 		 */
 		post_log("Abnormal voltage detected (GPIO62)\n");