dfu: cmd: trigger watchdog before calling usb_gadget_handle_interrupts

trigger watchdog before calling usb_gadget_handle_interrupts()
This prevents board resets when calling dfu command on boards
which have a watchdog.

Signed-off-by: Heiko Schocher <hs@denx.de>
[ Reedition by Lukasz Majewski <l.majewski@samsung.com> to apply to
v2014.04 release ]

common/cmd_dfu.c

@@ -9,6 +9,7 @@
  */
 
 #include <common.h>
+#include <watchdog.h>
 #include <dfu.h>
 #include <g_dnl.h>
 #include <usb.h>
@@ -64,6 +65,7 @@ static int do_dfu(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 		if (ctrlc())
 			goto exit;
 
+		WATCHDOG_RESET();
 		usb_gadget_handle_interrupts(controller_index);
 	}
 exit: