ACPI, APEI, ERST debug support

This patch adds debugging/testing support to ERST. A misc device is
implemented to export raw ERST read/write/clear etc operations to user
space. With this patch, we can add ERST testing support to
linuxfirmwarekit ISO (linuxfirmwarekit.org) to verify the kernel
support and the firmware implementation.

Signed-off-by: Huang Ying <ying.huang@intel.com>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/drivers/acpi/apei/Makefile b/drivers/acpi/apei/Makefile
index b13b03a..d1d1bc0 100644
--- a/drivers/acpi/apei/Makefile
+++ b/drivers/acpi/apei/Makefile
@@ -1,5 +1,6 @@
 obj-$(CONFIG_ACPI_APEI)		+= apei.o
 obj-$(CONFIG_ACPI_APEI_GHES)	+= ghes.o
 obj-$(CONFIG_ACPI_APEI_EINJ)	+= einj.o
+obj-$(CONFIG_ACPI_APEI_ERST_DEBUG) += erst-dbg.o
 
 apei-y := apei-base.o hest.o cper.o erst.o