memblock, x86: Make ARCH_DISCARD_MEMBLOCK a config option

From 6839454ae63f1eb21e515c10229ca95c22955fec Mon Sep 17 00:00:00 2001
From: Tejun Heo <tj@kernel.org>
Date: Thu, 14 Jul 2011 11:22:17 +0200

Make ARCH_DISCARD_MEMBLOCK a config option so that it can be handled
together with other MEMBLOCK options.

Signed-off-by: Tejun Heo <tj@kernel.org>
Link: http://lkml.kernel.org/r/20110714094603.GH3455@htj.dyndns.org
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
diff --git a/mm/Kconfig b/mm/Kconfig
index 30a5d47..7c56971 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -134,6 +134,9 @@
 config HAVE_MEMBLOCK_NODE_MAP
 	boolean
 
+config ARCH_DISCARD_MEMBLOCK
+	boolean
+
 # eventually, we can have this option just 'select SPARSEMEM'
 config MEMORY_HOTPLUG
 	bool "Allow for memory hot-add"