nb/intel/sandybridge: Add ACPI DMAR table

Add a DMAR table to advertise IOMMU and IRQ remapping capabilities to
the OS.

Tested with kontron/ktqm77. Under Linux, the table is detected and
interrupt remapping is enabled automatically.

Change-Id: Id6ee601a0a8543ed09c6bb8d308a3a3549fc34e5
Signed-off-by: Nico Huber <nico.huber@secunet.com>
Reviewed-on: http://review.coreboot.org/12195
Tested-by: build bot (Jenkins)
Reviewed-by: Duncan Laurie <dlaurie@google.com>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
diff --git a/src/northbridge/intel/sandybridge/sandybridge.h b/src/northbridge/intel/sandybridge/sandybridge.h
index 853dd1c..0a1f20a 100644
--- a/src/northbridge/intel/sandybridge/sandybridge.h
+++ b/src/northbridge/intel/sandybridge/sandybridge.h
@@ -62,6 +62,8 @@
 /* Everything below this line is ignored in the DSDT */
 #ifndef __ACPI__
 
+#include <rules.h>
+
 /* Device 0:0.0 PCI configuration space (Host Bridge) */
 
 #define EPBAR		0x40
@@ -215,6 +217,13 @@
 void report_platform_info(void);
 #endif /* !__SMM__ */
 
+#if ENV_RAMSTAGE
+#include <device/device.h>
+
+struct acpi_rsdp;
+unsigned long northbridge_write_acpi_tables(device_t device, unsigned long start, struct acpi_rsdp *rsdp);
+#endif
+
 
 #define MRC_DATA_ALIGN           0x1000
 #define MRC_DATA_SIGNATURE       (('M'<<0)|('R'<<8)|('C'<<16)|('D'<<24))