Fix MISRA rule 8.4 Part 1

Rule 8.4: A compatible declaration shall be visible when
          an object or function with external linkage is defined

Fixed for:
	make DEBUG=1 PLAT=fvp LOG_LEVEL=50 all

Change-Id: I7c2ad3f5c015411c202605851240d5347e4cc8c7
Signed-off-by: Roberto Vargas <roberto.vargas@arm.com>
diff --git a/include/common/desc_image_load.h b/include/common/desc_image_load.h
index f183db5..73aa27c 100644
--- a/include/common/desc_image_load.h
+++ b/include/common/desc_image_load.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2016-2018, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -19,6 +19,9 @@
 	bl_params_node_t params_node_mem;
 } bl_mem_params_node_t;
 
+extern bl_mem_params_node_t *bl_mem_params_desc_ptr;
+extern unsigned int bl_mem_params_desc_num;
+
 /*
  * Macro to register list of BL image descriptors,
  * defined as an array of bl_mem_params_node_t.