drm/exynos: add generic check for plane state

This patch adds generic check for plane state - display area dimensions,
so drivers can always assume that they get valid plane state to set.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-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_mixer.c b/drivers/gpu/drm/exynos/exynos_mixer.c
index a229f86..4190285 100644
--- a/drivers/gpu/drm/exynos/exynos_mixer.c
+++ b/drivers/gpu/drm/exynos/exynos_mixer.c
@@ -117,16 +117,19 @@
 		.type = DRM_PLANE_TYPE_PRIMARY,
 		.pixel_formats = mixer_formats,
 		.num_pixel_formats = ARRAY_SIZE(mixer_formats),
+		.capabilities = EXYNOS_DRM_PLANE_CAP_DOUBLE,
 	}, {
 		.zpos = 1,
 		.type = DRM_PLANE_TYPE_CURSOR,
 		.pixel_formats = mixer_formats,
 		.num_pixel_formats = ARRAY_SIZE(mixer_formats),
+		.capabilities = EXYNOS_DRM_PLANE_CAP_DOUBLE,
 	}, {
 		.zpos = 2,
 		.type = DRM_PLANE_TYPE_OVERLAY,
 		.pixel_formats = vp_formats,
 		.num_pixel_formats = ARRAY_SIZE(vp_formats),
+		.capabilities = EXYNOS_DRM_PLANE_CAP_SCALE,
 	},
 };