Add Fam10 Gart table walk enable recomended by the BKDG. 

Signed-off-by: Marc Jones <marc.jones@amd.com>

Index: coreboot-v2/src/cpu/amd/model_10xxx/defaults.h
===================================================================
--- coreboot-v2.orig/src/cpu/amd/model_10xxx/defaults.h	2008-04-23 17:08:42.000000000 -0600
+++ coreboot-v2/src/cpu/amd/model_10xxx/defaults.h	2008-04-23 17:10:19.000000000 -0600
@@ -46,6 +46,10 @@
 	  0xF << 19, 0x00000000,
 	  0xF << 19, 0x00000000 },	/* [RtryHt[0..3]]=1 */
 
+	{ MC4_CTL_MASK, AMD_DR_ALL, AMD_PTYPE_ALL,
+	  0x1 << 10, 0x00000000,
+	  0x1 << 10, 0x00000000 },	/* [GartTblWkEn]=1 */
+
 	{ DC_CFG, AMD_DR_ALL, AMD_PTYPE_SVR,
 	  0x00000000, 0x00000004,
 	  0x00000000, 0x0000000C },	/* [REQ_CTR] = 1 for Server */
