drm/tinydrm: Remove tinydrm_shutdown()

It's just a wrapper around drm_atomic_helper_shutdown() now.
Also store drm_device in the drvdata field, since that's what's used.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190210131039.52664-7-noralf@tronnes.org
diff --git a/drivers/gpu/drm/tinydrm/st7735r.c b/drivers/gpu/drm/tinydrm/st7735r.c
index 6c7904c..9b47d86 100644
--- a/drivers/gpu/drm/tinydrm/st7735r.c
+++ b/drivers/gpu/drm/tinydrm/st7735r.c
@@ -14,6 +14,7 @@
 #include <linux/spi/spi.h>
 #include <video/mipi_display.h>
 
+#include <drm/drm_atomic_helper.h>
 #include <drm/drm_drv.h>
 #include <drm/drm_gem_cma_helper.h>
 #include <drm/drm_gem_framebuffer_helper.h>
@@ -183,16 +184,14 @@ static int st7735r_probe(struct spi_device *spi)
 	if (ret)
 		return ret;
 
-	spi_set_drvdata(spi, mipi);
+	spi_set_drvdata(spi, mipi->tinydrm.drm);
 
 	return devm_tinydrm_register(&mipi->tinydrm);
 }
 
 static void st7735r_shutdown(struct spi_device *spi)
 {
-	struct mipi_dbi *mipi = spi_get_drvdata(spi);
-
-	tinydrm_shutdown(&mipi->tinydrm);
+	drm_atomic_helper_shutdown(spi_get_drvdata(spi));
 }
 
 static struct spi_driver st7735r_spi_driver = {