cert_create: Remove some unused header files inclusions

The chain of trust definitions are only needed in the part of the code
dealing with the TBBR CoT (tbbr/* files).

Change-Id: I6f9a86bba4a2d16313b6842a3ec85b7c951074bc
Signed-off-by: Sandrine Bailleux <sandrine.bailleux@arm.com>
diff --git a/tools/cert_create/src/key.c b/tools/cert_create/src/key.c
index 0f80cce..fcc9d53 100644
--- a/tools/cert_create/src/key.c
+++ b/tools/cert_create/src/key.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015-2019, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2015-2020, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -13,12 +13,6 @@
 #include <openssl/evp.h>
 #include <openssl/pem.h>
 
-#if USE_TBBR_DEFS
-#include <tbbr_oid.h>
-#else
-#include <platform_oid.h>
-#endif
-
 #include "cert.h"
 #include "cmd_opt.h"
 #include "debug.h"