plat/arm: Load and populate fw_config and tb_fw_config

Modified the code to do below changes:

1. Load tb_fw_config along with fw_config by BL1.
2. Populate fw_config device tree information in the
   BL1 to load tb_fw_config.
3. In BL2, populate fw_config information to retrieve
   the address of tb_fw_config and then tb_fw_config
   gets populated using retrieved address.
4. Avoid processing of configuration file in case of error
   value returned from "fw_config_load" function.
5. Updated entrypoint information for BL2 image so
   that it's arg0 should point to fw_config address.

Signed-off-by: Manish V Badarkhe <Manish.Badarkhe@arm.com>
Signed-off-by: Louis Mayencourt <louis.mayencourt@arm.com>
Change-Id: Ife6f7b673a074e7f544ee3d1bda7645fd5b2886c
diff --git a/lib/fconf/fconf.c b/lib/fconf/fconf.c
index affec54..bc4fa8e 100644
--- a/lib/fconf/fconf.c
+++ b/lib/fconf/fconf.c
@@ -29,8 +29,11 @@
 	};
 
 	config_info = FCONF_GET_PROPERTY(dyn_cfg, dtb, image_id);
+	assert(config_info != NULL);
+
 	config_image_info.image_base = config_info->config_addr;
-	config_image_info.image_max_size = (uint32_t)config_info->config_max_size;
+	config_image_info.image_max_size =
+		(uint32_t)config_info->config_max_size;
 
 	VERBOSE("FCONF: Loading config with image ID: %d\n", image_id);
 	err = load_auth_image(image_id, &config_image_info);