drm/i915: do not set MOCS control values on dgfx

On dgfx there's no LLC and eDRAM control table. Since now this
also means the device has global MOCS, just return early on the
initialization function.

L3 settings still apply and still need to be tweaked.

Bspec: 45101

Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191024195122.22877-3-lucas.demarchi@intel.com

drivers/gpu/drm/i915/gt/intel_mocs.c

@@ -462,6 +462,12 @@ static void intel_mocs_init_global(struct intel_gt *gt)
 	struct drm_i915_mocs_table table;
 	unsigned int index;
 
+	/*
+	 * LLC and eDRAM control values are not applicable to dgfx
+	 */
+	if (IS_DGFX(gt->i915))
+		return;
+
 	GEM_BUG_ON(!HAS_GLOBAL_MOCS_REGISTERS(gt->i915));
 
 	if (!get_mocs_settings(gt->i915, &table))