drm/exynos: Add the dependency for DRM_EXYNOS to DPI/DSI/DP

Without this dependency, Kbuild is confused and the configs below
them are not placed under Exynos DRM. This patch fixes it, so the
configs below them become to be placed under Exynos DRM.
Signed-off-by: Hyungwon Hwang <human.hwang@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>

drivers/gpu/drm/exynos/Kconfig

@@ -33,7 +33,7 @@ config DRM_EXYNOS7_DECON
 
 config DRM_EXYNOS_DPI
 	bool "EXYNOS DRM parallel output support"
-	depends on (DRM_EXYNOS_FIMD || DRM_EXYNOS7_DECON)
+	depends on DRM_EXYNOS && (DRM_EXYNOS_FIMD || DRM_EXYNOS7_DECON)
 	select DRM_PANEL
 	default n
 	help
@@ -41,7 +41,7 @@ config DRM_EXYNOS_DPI
 
 config DRM_EXYNOS_DSI
 	bool "EXYNOS DRM MIPI-DSI driver support"
-	depends on (DRM_EXYNOS_FIMD || DRM_EXYNOS7_DECON)
+	depends on DRM_EXYNOS && (DRM_EXYNOS_FIMD || DRM_EXYNOS7_DECON)
 	select DRM_MIPI_DSI
 	select DRM_PANEL
 	default n
@@ -50,7 +50,7 @@ config DRM_EXYNOS_DSI
 
 config DRM_EXYNOS_DP
 	bool "EXYNOS DRM DP driver support"
-	depends on (DRM_EXYNOS_FIMD || DRM_EXYNOS7_DECON) && (DRM_PTN3460=n || DRM_PTN3460=y || DRM_PTN3460=DRM_EXYNOS)
+	depends on DRM_EXYNOS && (DRM_EXYNOS_FIMD || DRM_EXYNOS7_DECON) && (DRM_PTN3460=n || DRM_PTN3460=y || DRM_PTN3460=DRM_EXYNOS)
 	default DRM_EXYNOS
 	select DRM_PANEL
 	help