drm/i915: Wait for object idle without locks in atomic_commit, v2.

Make pinning and waiting a separate step, and wait for object idle
without struct_mutex held.

Changes since v1:
- Do not wait when a reset is in progress.
- Remove call to i915_gem_object_wait_rendering for
  intel_overlay_do_put_image (Chris Wilson)

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>

drivers/gpu/drm/i915/i915_gem.c

@@ -3883,17 +3883,11 @@ unlock:
 int
 i915_gem_object_pin_to_display_plane(struct drm_i915_gem_object *obj,
 				     u32 alignment,
-				     struct intel_engine_cs *pipelined,
-				     struct drm_i915_gem_request **pipelined_request,
 				     const struct i915_ggtt_view *view)
 {
 	u32 old_read_domains, old_write_domain;
 	int ret;
 
-	ret = i915_gem_object_sync(obj, pipelined, pipelined_request);
-	if (ret)
-		return ret;
-
 	/* Mark the pin_display early so that we account for the
 	 * display coherency whilst setting up the cache domains.
 	 */