mkimage: Honour the default image type with auto-fit

The default image type is supposed to be IH_TYPE_KERNEL, as set in the
'params' variable. Honour this with auto-fit also.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@konsulko.com>

tools/mkimage.c

@@ -272,7 +272,7 @@ static void process_args(int argc, char **argv)
 	 * will always be IH_TYPE_FLATDT in this case).
 	 */
 	if (params.type == IH_TYPE_FLATDT) {
-		params.fit_image_type = type;
+		params.fit_image_type = type ? type : IH_TYPE_KERNEL;
 		if (!params.auto_its)
 			params.datafile = datafile;
 	} else if (type != IH_TYPE_INVALID) {