drm/rcar-du: prepare for drmP.h removal from drm_modeset_helper.h

The use of drmP.h is discouraged and removal of it from
drm_modeset_helper.h caused rcar-du to fail to build.

This patch introduce the necessary fixes to prepare for the
drmP.h removal from drm_modeset_helper.h.

Build tested on arm allmodconfig/allyesconfig.

v2:
- new patch. Changes like drm_probe_helper and other
  required several updates
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: linux-renesas-soc@vger.kernel.org
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20190126122527.11647-4-sam@ravnborg.org

drivers/gpu/drm/rcar-du/rcar_du_crtc.c

@@ -9,14 +9,17 @@
 
 #include <linux/clk.h>
 #include <linux/mutex.h>
+#include <linux/platform_device.h>
 #include <linux/sys_soc.h>
 
 #include <drm/drm_atomic.h>
 #include <drm/drm_atomic_helper.h>
 #include <drm/drm_crtc.h>
+#include <drm/drm_device.h>
 #include <drm/drm_fb_cma_helper.h>
 #include <drm/drm_gem_cma_helper.h>
 #include <drm/drm_plane_helper.h>
+#include <drm/drm_vblank.h>
 
 #include "rcar_du_crtc.h"
 #include "rcar_du_drv.h"

drivers/gpu/drm/rcar-du/rcar_du_drv.c

@@ -20,6 +20,7 @@
 #include <drm/drm_atomic_helper.h>
 #include <drm/drm_fb_cma_helper.h>
 #include <drm/drm_fb_helper.h>
+#include <drm/drm_drv.h>
 #include <drm/drm_gem_cma_helper.h>
 #include <drm/drm_probe_helper.h>
 

drivers/gpu/drm/rcar-du/rcar_du_kms.c

@@ -10,10 +10,12 @@
 #include <drm/drm_atomic.h>
 #include <drm/drm_atomic_helper.h>
 #include <drm/drm_crtc.h>
+#include <drm/drm_device.h>
 #include <drm/drm_fb_cma_helper.h>
 #include <drm/drm_gem_cma_helper.h>
 #include <drm/drm_gem_framebuffer_helper.h>
 #include <drm/drm_probe_helper.h>
+#include <drm/drm_vblank.h>
 
 #include <linux/of_graph.h>
 #include <linux/wait.h>

drivers/gpu/drm/rcar-du/rcar_du_plane.c

@@ -10,7 +10,9 @@
 #include <drm/drm_atomic.h>
 #include <drm/drm_atomic_helper.h>
 #include <drm/drm_crtc.h>
+#include <drm/drm_device.h>
 #include <drm/drm_fb_cma_helper.h>
+#include <drm/drm_fourcc.h>
 #include <drm/drm_gem_cma_helper.h>
 #include <drm/drm_plane_helper.h>
 

drivers/gpu/drm/rcar-du/rcar_du_vsp.c

@@ -13,6 +13,7 @@
 #include <drm/drm_gem_cma_helper.h>
 #include <drm/drm_gem_framebuffer_helper.h>
 #include <drm/drm_plane_helper.h>
+#include <drm/drm_vblank.h>
 
 #include <linux/bitops.h>
 #include <linux/dma-mapping.h>