x86: Add device tree support

This patch adds minimal support for device tree on x86. The device
tree blob is passed to the kernel via setup_data which requires at
least boot protocol 2.09.

Memory size, restricted memory regions, boot arguments are gathered
the traditional way so things like cmd_line are just here to let the
code compile.

The current plan is use the device tree as an extension and to gather
information which can not be enumerated and would have to be hardcoded
otherwise. This includes things like 
   - which devices are on this I2C/SPI bus?
   - how are the interrupts wired to IO APIC?
   - where could my hpet be?

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Dirk Brandewie <dirk.brandewie@gmail.com>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Cc: sodaville@linutronix.de
Cc: devicetree-discuss@lists.ozlabs.org
LKML-Reference: <1298405266-1624-3-git-send-email-bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index efbae0c..b4c2e9c 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -382,6 +382,8 @@
 	depends on X86_32
 	depends on X86_EXTENDED_PLATFORM
 	select X86_REBOOTFIXUPS
+	select OF
+	select OF_EARLY_FLATTREE
 	---help---
 	  Select for the Intel CE media processor (CE4100) SOC.
 	  This option compiles in support for the CE4100 SOC for settop