drm/i915/dsb: Remove PIN_MAPPABLE from the DSB object VMA

It sounds like the hardware only needs the DSB object to be in global GTT
and not in the mappable region.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Animesh Manna <animesh.manna@intel.com>
Reviewed-by: Animesh Manna <animesh.manna@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191017155810.21654-1-tvrtko.ursulin@linux.intel.com

drivers/gpu/drm/i915/display/intel_dsb.c

@@ -119,7 +119,7 @@ intel_dsb_get(struct intel_crtc *crtc)
 		goto err;
 	}
 
-	vma = i915_gem_object_ggtt_pin(obj, NULL, 0, 0, PIN_MAPPABLE);
+	vma = i915_gem_object_ggtt_pin(obj, NULL, 0, 0, 0);
 	if (IS_ERR(vma)) {
 		DRM_ERROR("Vma creation failed\n");
 		i915_gem_object_put(obj);