northbridge/amd/amdfam10: Rename mislabeled iommu nvram option to gart

Change-Id: Ia24102e164eb5753ade3f9b5ab21eba2fa60836b
Signed-off-by: Timothy Pearson <tpearson@raptorengineeringinc.com>
Reviewed-on: http://review.coreboot.org/12046
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martinroth@google.com>
diff --git a/src/mainboard/supermicro/h8scm_fam10/cmos.layout b/src/mainboard/supermicro/h8scm_fam10/cmos.layout
index 0ad18a2..bf58aac 100644
--- a/src/mainboard/supermicro/h8scm_fam10/cmos.layout
+++ b/src/mainboard/supermicro/h8scm_fam10/cmos.layout
@@ -12,7 +12,7 @@
 412          4       e       6        debug_level
 440          4       e       9        slow_cpu
 444          1       e       1        nmi
-445          1       e       1        iommu
+445          1       e       1        gart
 456          1       e       1        ECC_memory
 728        256       h       0        user_data
 984         16       h       0        check_sum