drm/stm: ltdc: manage the get_irq probe defer case

Manage the -EPROBE_DEFER error case for the ltdc IRQ.
Signed-off-by: Fabien Dessenne <fabien.dessenne@st.com>
Acked-by: Philippe Cornu <philippe.cornu@st.com>
Signed-off-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/1556114601-30936-2-git-send-email-fabien.dessenne@st.com

drivers/gpu/drm/stm/ltdc.c

@@ -1174,6 +1174,9 @@ int ltdc_load(struct drm_device *ddev)
 
 	for (i = 0; i < MAX_IRQ; i++) {
 		irq = platform_get_irq(pdev, i);
+		if (irq == -EPROBE_DEFER)
+			goto err;
+
 		if (irq < 0)
 			continue;