DRM: Armada: implement lastclose() for fbhelper

Call drm_fb_helper_restore_fbdev_mode() upon last close so that in the
event of the X server crashing, we have some kind of mode restored.

Reviewed-by: Rob Clark <robdclark@gmail.com>
Reviewed-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/drivers/gpu/drm/armada/armada_drv.c b/drivers/gpu/drm/armada/armada_drv.c
index 7aede90..15425d2 100644
--- a/drivers/gpu/drm/armada/armada_drv.c
+++ b/drivers/gpu/drm/armada/armada_drv.c
@@ -321,6 +321,11 @@
 		DRM_UNLOCKED),
 };
 
+static void armada_drm_lastclose(struct drm_device *dev)
+{
+	armada_fbdev_lastclose(dev);
+}
+
 static const struct file_operations armada_drm_fops = {
 	.owner			= THIS_MODULE,
 	.llseek			= no_llseek,
@@ -337,7 +342,7 @@
 	.open			= NULL,
 	.preclose		= NULL,
 	.postclose		= NULL,
-	.lastclose		= NULL,
+	.lastclose		= armada_drm_lastclose,
 	.unload			= armada_drm_unload,
 	.get_vblank_counter	= drm_vblank_count,
 	.enable_vblank		= armada_drm_enable_vblank,