drm/exynos/dpi: stop using display->ctx pointer

The patch replaces accesses to display->ctx pointer by container_of
construct. The field is removed as well as dpi was the last user of it.

Signed-off-by: Andrzej Hajda <[e-mail]>
Signed-off-by: Inki Dae <[e-mail]>

drivers/gpu/drm/exynos/exynos_drm_dpi.c

···
 static int exynos_dpi_create_connector(struct exynos_drm_display *display,
 				       struct drm_encoder *encoder)
 {
-	struct exynos_dpi *ctx = display->ctx;
+	struct exynos_dpi *ctx = display_to_dpi(display);
 	struct drm_connector *connector = &ctx->connector;
 	int ret;
 
···
 
 static void exynos_dpi_dpms(struct exynos_drm_display *display, int mode)
 {
-	struct exynos_dpi *ctx = display->ctx;
+	struct exynos_dpi *ctx = display_to_dpi(display);
 
 	switch (mode) {
 	case DRM_MODE_DPMS_ON:
···
 	ctx->display.type = EXYNOS_DISPLAY_TYPE_LCD;
 	ctx->display.ops = &exynos_dpi_display_ops;
 	ctx->dev = dev;
-	ctx->display.ctx = ctx;
 	ctx->dpms_mode = DRM_MODE_DPMS_OFF;
 
 	ret = exynos_drm_component_add(dev,

drivers/gpu/drm/exynos/exynos_drm_drv.h

···
 	struct drm_encoder *encoder;
 	struct drm_connector *connector;
 	struct exynos_drm_display_ops *ops;
-	void *ctx;
 };
 
 /*