x86: coreboot: Set CONFIG_ARCH_DEVICE_TREE correctly

We will use coreboot.dtsi as our fdt include file.

Signed-off-by: Gabe Black <gabeblack@chromium.org>

Signed-off-by: Simon Glass <sjg@chromium.org>

arch/x86/cpu/coreboot/config.mk

@@ -0,0 +1,23 @@
+#
+# Copyright (c) 2012 The Chromium OS Authors.
+#
+# See file CREDITS for list of people who contributed to this
+# project.
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License as
+# published by the Free Software Foundation; either version 2 of
+# the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+# MA 02111-1307 USA
+#
+
+CONFIG_ARCH_DEVICE_TREE := coreboot