agp/intel: fix cache control for sandybridge

This is broken from 97ef1bdd.
Let's set the correct bit for LLC+MLC and LLC only.
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

drivers/char/agp/intel-gtt.c

@@ -1291,11 +1291,11 @@ static void gen6_write_entry(dma_addr_t addr, unsigned int entry,
 	if (type_mask == AGP_USER_UNCACHED_MEMORY)
 		pte_flags = GEN6_PTE_UNCACHED | I810_PTE_VALID;
 	else if (type_mask == AGP_USER_CACHED_MEMORY_LLC_MLC) {
-		pte_flags = GEN6_PTE_LLC | I810_PTE_VALID;
+		pte_flags = GEN6_PTE_LLC_MLC | I810_PTE_VALID;
 		if (gfdt)
 			pte_flags |= GEN6_PTE_GFDT;
 	} else { /* set 'normal'/'cached' to LLC by default */
-		pte_flags = GEN6_PTE_LLC_MLC | I810_PTE_VALID;
+		pte_flags = GEN6_PTE_LLC | I810_PTE_VALID;
 		if (gfdt)
 			pte_flags |= GEN6_PTE_GFDT;
 	}