drm/exynos: remove struct *_win_data abstraction on planes

struct {fimd,mixer,vidi}_win_data was just keeping the same data
as struct exynos_drm_plane thus get ride of it and use exynos_drm_plane
directly.

It changes how planes are created and remove .win_mode_set() callback
that was only filling all *_win_data structs.

v2: check for return of exynos_plane_init()

Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: Inki Dae <inki.dae@samsung.com>
diff --git a/drivers/gpu/drm/exynos/exynos_drm_crtc.h b/drivers/gpu/drm/exynos/exynos_drm_crtc.h
index 6258b80..e1fd2ef 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_crtc.h
+++ b/drivers/gpu/drm/exynos/exynos_drm_crtc.h
@@ -18,6 +18,7 @@
 #include "exynos_drm_drv.h"
 
 struct exynos_drm_crtc *exynos_drm_crtc_create(struct drm_device *drm_dev,
+					       struct drm_plane *plane,
 					       int pipe,
 					       enum exynos_drm_output_type type,
 					       struct exynos_drm_crtc_ops *ops,