Fix vboot_reference-firmware linking error

firmware/stub/include/biosincludes.h

 /* Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 #ifndef CHROMEOS_SRC_PLATFORM_VBOOT_REFERENCE_FIRMWARE_STUB_BIOSINCLUDES_H_
 #define CHROMEOS_SRC_PLATFORM_VBOOT_REFERENCE_FIRMWARE_STUB_BIOSINCLUDES_H_
 
 /*
  * This file is a placeholder for the includes supplied by the BIOS
  * compilation environment. This file is included if and only if
  * CHROMEOS_ENVIRONMENT is not defined at compilation time.
  */
 
 #ifdef TARGET_TEST_MODE
 
 typedef unsigned long long uint64_t;
 typedef long long int64_t;
 typedef unsigned int uint32_t;
 typedef unsigned short uint16_t;
 typedef unsigned char uint8_t;
 typedef unsigned size_t;
 
 #ifndef NULL
 #define NULL ((void*) 0)
 #endif
 
+#define UINT32_C(x) ((uint32_t)x)
 #define UINT64_C(x) ((uint64_t)x)
 #define __attribute__(x)
 #define PRIu64 "llu"
 extern void debug(const char *format, ...);
 
 #define POSSIBLY_UNUSED
 #define INLINE
 
 #endif
 
 #endif /*CHROMEOS_SRC_PLATFORM_VBOOT_REFERENCE_FIRMWARE_STUB_BIOSINCLUDES_H_*/