drm/vc4: hdmi: Silence pixel clock error on -EPROBE_DEFER

If the vc4 hdmi driver loads before the pixel clock is available we
see a spurious "*ERROR* Failed to get pixel clock" error.
Signed-off-by: James Hilliard <james.hilliard1@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20200525012859.267433-1-james.hilliard1@gmail.com

drivers/gpu/drm/vc4/vc4_hdmi.c

@@ -1330,8 +1330,10 @@ static int vc4_hdmi_bind(struct device *dev, struct device *master, void *data)
 
 	hdmi->pixel_clock = devm_clk_get(dev, "pixel");
 	if (IS_ERR(hdmi->pixel_clock)) {
-		DRM_ERROR("Failed to get pixel clock\n");
-		return PTR_ERR(hdmi->pixel_clock);
+		ret = PTR_ERR(hdmi->pixel_clock);
+		if (ret != -EPROBE_DEFER)
+			DRM_ERROR("Failed to get pixel clock\n");
+		return ret;
 	}
 	hdmi->hsm_clock = devm_clk_get(dev, "hdmi");
 	if (IS_ERR(hdmi->hsm_clock)) {