Add VBDEBUG macro for debug output.

Makefile

 # 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.
 
 export CC ?= gcc
 export CXX ?= g++
-export CFLAGS = -Wall -DNDEBUG -O3 -Werror -DCHROMEOS_ENVIRONMENT
+export CFLAGS = -Wall -DNDEBUG -O3 -Werror -DCHROMEOS_ENVIRONMENT \
+        -DVBOOT_DEBUG
 export TOP = $(shell pwd)
 export FWDIR=$(TOP)/firmware
 export HOSTDIR=$(TOP)/host
 export INCLUDES = -I$(FWDIR)/include -I$(FWDIR)/stub/include
 
 export BUILD = ${TOP}/build
 export FWLIB = ${BUILD}/vboot_fw.a
 export HOSTLIB= ${BUILD}/vboot_host.a
 
 SUBDIRS = firmware host utility cgpt tests
@@ skipping 13 matching lines @@
 
 clean:
         /bin/rm -rf ${BUILD}
 
 install:
         $(MAKE) -C utility install
         $(MAKE) -C cgpt install
 
 runtests:
         $(MAKE) -C tests runtests