drm/exynos: Ensure suspended runtime PM state during system suspend

Add calls to pm_runtime_force_{suspend,resume} as SYSTEM_SLEEP_PM_OPS for
all drivers for the real Exynos DRM hardware modules. This ensures that
the resources will be released for the system PM suspend/resume cycle.
Exynos DRM core already takes care of suspending the whole display pipeline
before PM callbacks of the real devices are called.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>
diff --git a/drivers/gpu/drm/exynos/exynos_drm_dsi.c b/drivers/gpu/drm/exynos/exynos_drm_dsi.c
index a1ed614..781b82c 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_dsi.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_dsi.c
@@ -1863,6 +1863,8 @@
 
 static const struct dev_pm_ops exynos_dsi_pm_ops = {
 	SET_RUNTIME_PM_OPS(exynos_dsi_suspend, exynos_dsi_resume, NULL)
+	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
+				pm_runtime_force_resume)
 };
 
 struct platform_driver dsi_driver = {