iris: Fix BLORP vertex buffers to respect ISL MOCS settings

Fixes: a4da6008b6 ("iris: Use mocs from isl_dev.")
Reviewed-by: Tapani Pälli <tapani.palli@intel.com>
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/merge_requests/3720>

src/gallium/drivers/iris/iris_blorp.c

@@ -46,12 +46,6 @@
 #define BLORP_USE_SOFTPIN
 #include "blorp/blorp_genX_exec.h"
 
-#if GEN_GEN == 8
-#define MOCS_WB 0x78
-#else
-#define MOCS_WB (2 << 1)
-#endif
-
 static uint32_t *
 stream_state(struct iris_batch *batch,
              struct u_upload_mgr *uploader,
@@ -189,7 +183,7 @@ blorp_alloc_vertex_buffer(struct blorp_batch *blorp_batch,
    *addr = (struct blorp_address) {
       .buffer = bo,
       .offset = offset,
-      .mocs = MOCS_WB,
+      .mocs = iris_mocs(bo, &batch->screen->isl_dev),
    };
 
    return map;