Revert "common: spl_fit: Default to IH_OS_U_BOOT if FIT_IMAGE_TINY enabled"

Commit cf8dcc5d ("common: spl_fit: Default to IH_OS_U_BOOT if
FIT_IMAGE_TINY enabled") is not correct, it will append fdt to each loadable
image. Actually when using TINY FIT, the first loadable image is thought as
u-boot and already have fdt appended.

Signed-off-by: Ye Li <ye.li@nxp.com>
Tested-by: Fabio Estevam <festevam@gmail.com>

common/spl/spl_fit.c

@@ -517,10 +517,6 @@ int spl_load_simple_fit(struct spl_image_info *spl_image,
 
 		if (!spl_fit_image_get_os(fit, node, &os_type))
 			debug("Loadable is %s\n", genimg_get_os_name(os_type));
-#if CONFIG_IS_ENABLED(FIT_IMAGE_TINY)
-		else
-			os_type = IH_OS_U_BOOT;
-#endif
 
 		if (os_type == IH_OS_U_BOOT) {
 			spl_fit_append_fdt(&image_info, info, sector,