drm/exynos: mixer: also allow NV21 for the video processor

All the necessary code is already there, just need to
handle the format in the switch statement.

Signed-off-by: Tobias Jakobi <tjakobi@math.uni-bielefeld.de>
Acked-by: Joonyoung Shim <jy0922.shim@samsung.com>
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 1e8ce9e..adb5ec1 100644
--- a/drivers/gpu/drm/exynos/exynos_mixer.c
+++ b/drivers/gpu/drm/exynos/exynos_mixer.c
@@ -393,6 +393,9 @@
 	case DRM_FORMAT_NV12:
 		crcb_mode = false;
 		break;
+	case DRM_FORMAT_NV21:
+		crcb_mode = true;
+		break;
 	default:
 		DRM_ERROR("pixel format for vp is wrong [%d].\n",
 				plane->pixel_format);