drivers/edac: add new nmi rescan

Provides a way for NMI reported errors on x86 to notify the EDAC
subsystem pending ECC errors by writing to a software state variable.

Here's the reworked patch. I added an EDAC stub to the kernel so we can
have variables that are in the kernel even if EDAC is a module. I also
implemented the idea of using the chip driver to select error detection
mode via module parameter and eliminate the kernel compile option.
Please review/test. Thx!

Also, I only made changes to some of the chipset drivers since I am
unfamiliar with the other ones. We can add similar changes as we go.

Signed-off-by: Dave Jiang <djiang@mvista.com>
Signed-off-by: Douglas Thompson <dougthompson@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/edac/Makefile b/drivers/edac/Makefile
index 773472c..19d5ac7 100644
--- a/drivers/edac/Makefile
+++ b/drivers/edac/Makefile
@@ -5,9 +5,9 @@
 # This file may be distributed under the terms of the
 # GNU General Public License.
 #
-# $Id: Makefile,v 1.4.2.3 2005/07/08 22:05:38 dsp_llnl Exp $
 
 
+obj-$(CONFIG_EDAC)			:= edac_stub.o
 obj-$(CONFIG_EDAC_MM_EDAC)		+= edac_core.o
 
 edac_core-objs	:= edac_mc.o edac_device.o edac_mc_sysfs.o edac_pci_sysfs.o