Build: rename FIP_ADD_IMG to TOOL_ADD_IMG

Now FIP_ADD_IMG takes care of both fiptool and cert_create
symmetrically.  Rename it so that it matches the behavior.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
diff --git a/plat/hisilicon/hikey/platform.mk b/plat/hisilicon/hikey/platform.mk
index c8a2992..802c79c 100644
--- a/plat/hisilicon/hikey/platform.mk
+++ b/plat/hisilicon/hikey/platform.mk
@@ -1,5 +1,5 @@
 #
-# Copyright (c) 2017, ARM Limited and Contributors. All rights reserved.
+# Copyright (c) 2017-2018, ARM Limited and Contributors. All rights reserved.
 #
 # SPDX-License-Identifier: BSD-3-Clause
 #
@@ -36,10 +36,10 @@
 # Add the build options to pack Trusted OS Extra1 and Trusted OS Extra2 images
 # in the FIP if the platform requires.
 ifneq ($(BL32_EXTRA1),)
-$(eval $(call FIP_ADD_IMG,BL32_EXTRA1,--tos-fw-extra1))
+$(eval $(call TOOL_ADD_IMG,BL32_EXTRA1,--tos-fw-extra1))
 endif
 ifneq ($(BL32_EXTRA2),)
-$(eval $(call FIP_ADD_IMG,BL32_EXTRA2,--tos-fw-extra2))
+$(eval $(call TOOL_ADD_IMG,BL32_EXTRA2,--tos-fw-extra2))
 endif
 
 ENABLE_PLAT_COMPAT	:=	0