drm/imx: switch to universal planes

Use drm_universal_plane_init to create the planes, create the primary
plane first and use drm_crtc_init_with_planes to associate it with
the crtc.
This gets rid of the unused fallback primary plane previously created
by drm_crtc_init and fixes a NULL pointer dereference issue that can
be triggered by a modeset from userspace when fbdev helpers are
enabled [1].

[1] https://lkml.org/lkml/2015/11/4/107

Reported-by: Liu Ying <Ying.Liu@freescale.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Acked-by: Liu Ying <Ying.Liu@freescale.com>
diff --git a/drivers/gpu/drm/imx/ipuv3-plane.c b/drivers/gpu/drm/imx/ipuv3-plane.c
index 575f4c8..e2ff410 100644
--- a/drivers/gpu/drm/imx/ipuv3-plane.c
+++ b/drivers/gpu/drm/imx/ipuv3-plane.c
@@ -381,7 +381,7 @@
 
 struct ipu_plane *ipu_plane_init(struct drm_device *dev, struct ipu_soc *ipu,
 				 int dma, int dp, unsigned int possible_crtcs,
-				 bool priv)
+				 enum drm_plane_type type)
 {
 	struct ipu_plane *ipu_plane;
 	int ret;
@@ -399,10 +399,9 @@
 	ipu_plane->dma = dma;
 	ipu_plane->dp_flow = dp;
 
-	ret = drm_plane_init(dev, &ipu_plane->base, possible_crtcs,
-			     &ipu_plane_funcs, ipu_plane_formats,
-			     ARRAY_SIZE(ipu_plane_formats),
-			     priv);
+	ret = drm_universal_plane_init(dev, &ipu_plane->base, possible_crtcs,
+				       &ipu_plane_funcs, ipu_plane_formats,
+				       ARRAY_SIZE(ipu_plane_formats), type);
 	if (ret) {
 		DRM_ERROR("failed to initialize plane\n");
 		kfree(ipu_plane);