fix(bl2): correct messages with image_id

As image_id is unsigned, we have to use %u and not %d.
This avoids warning when -Wformat-signedness is enabled.

Change-Id: I3f868f3d14c9f19349f0daa8a754179f887339c0
Signed-off-by: Yann Gautier <yann.gautier@st.com>
diff --git a/bl2/bl2_image_load_v2.c b/bl2/bl2_image_load_v2.c
index 48c9bec..dee3fc2 100644
--- a/bl2/bl2_image_load_v2.c
+++ b/bl2/bl2_image_load_v2.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016-2020, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2016-2022, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -7,17 +7,16 @@
 #include <assert.h>
 #include <stdint.h>
 
-#include <platform_def.h>
-
 #include <arch.h>
 #include <arch_helpers.h>
+#include "bl2_private.h"
 #include <common/bl_common.h>
 #include <common/debug.h>
 #include <common/desc_image_load.h>
 #include <drivers/auth/auth_mod.h>
 #include <plat/common/platform.h>
 
-#include "bl2_private.h"
+#include <platform_def.h>
 
 /*******************************************************************************
  * This function loads SCP_BL2/BL3x images and returns the ep_info for
@@ -66,16 +65,16 @@
 
 		if ((bl2_node_info->image_info->h.attr &
 		    IMAGE_ATTRIB_SKIP_LOADING) == 0U) {
-			INFO("BL2: Loading image id %d\n", bl2_node_info->image_id);
+			INFO("BL2: Loading image id %u\n", bl2_node_info->image_id);
 			err = load_auth_image(bl2_node_info->image_id,
 				bl2_node_info->image_info);
 			if (err != 0) {
-				ERROR("BL2: Failed to load image id %d (%i)\n",
+				ERROR("BL2: Failed to load image id %u (%i)\n",
 				      bl2_node_info->image_id, err);
 				plat_error_handler(err);
 			}
 		} else {
-			INFO("BL2: Skip loading image id %d\n", bl2_node_info->image_id);
+			INFO("BL2: Skip loading image id %u\n", bl2_node_info->image_id);
 		}
 
 		/* Allow platform to handle image information. */