Fix MISRA rule 8.4 in common code

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

Change-Id: I26e042cb251a6f9590afa1340fdac73e42f23979
Signed-off-by: Roberto Vargas <roberto.vargas@arm.com>
diff --git a/bl2/bl2_private.h b/bl2/bl2_private.h
index ea2f33a..50295d6 100644
--- a/bl2/bl2_private.h
+++ b/bl2/bl2_private.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2017, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2013-2018, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -17,6 +17,6 @@
  *****************************************/
 void bl2_arch_setup(void);
 struct entry_point_info *bl2_load_images(void);
-void bl2_run_next_image(const entry_point_info_t *bl_ep_info);
+void bl2_run_next_image(const struct entry_point_info *bl_ep_info);
 
 #endif /* __BL2_PRIVATE_H__ */