drm/exynos: Add dependency for G2D in Kconfig

Select Exynos DRM based G2D only if non-DRM based Exynos G2D driver
is not selected.
Signed-off-by: NSachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: NInki Dae <inki.dae@samsung.com>

drivers/gpu/drm/exynos/Kconfig

@@ -36,6 +36,6 @@ config DRM_EXYNOS_VIDI
 
 config DRM_EXYNOS_G2D
 	bool "Exynos DRM G2D"
-	depends on DRM_EXYNOS
+	depends on DRM_EXYNOS && !VIDEO_SAMSUNG_S5P_G2D
 	help
 	  Choose this option if you want to use Exynos G2D for DRM.