display5: wdt: Enable WDT support (both SPL and u-boot)

Test case:

The fitImage gets corrupted:

truncate -c -s 3M fitImage
run tftp_mmc_fitImg
setenv boot_os y
reset

[board shall hang in SPL with
"Trying to boot from MMC1" information]

Then after X seconds WDT is causing board to reset. After N boot attempts
we enter recovery mode.

Signed-off-by: Lukasz Majewski <lukma@denx.de>
diff --git a/board/liebherr/display5/spl.c b/board/liebherr/display5/spl.c
index 551a143..5c6b8bf 100644
--- a/board/liebherr/display5/spl.c
+++ b/board/liebherr/display5/spl.c
@@ -21,6 +21,7 @@
 #include <fsl_esdhc.h>
 #include <netdev.h>
 #include <bootcount.h>
+#include <watchdog.h>
 #include "common.h"
 
 DECLARE_GLOBAL_DATA_PTR;
@@ -197,6 +198,10 @@
 
 	displ5_set_iomux_misc_spl();
 
+	/* Initialize and reset WDT in SPL */
+	hw_watchdog_init();
+	WATCHDOG_RESET();
+
 	/* load/boot image from boot device */
 	board_init_r(NULL, 0);
 }