drm/tinydrm: Use .dumb_map_offset and .dumb_destroy defaults

tinydrm can use the drm_driver.dumb_destroy and
drm_driver.dumb_map_offset defaults, so no need to set them.
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/1500837417-40580-22-git-send-email-noralf@tronnes.org

include/drm/tinydrm/tinydrm.h

@@ -56,9 +56,7 @@ pipe_to_tinydrm(struct drm_simple_display_pipe *pipe)
 	.gem_prime_vmap		= drm_gem_cma_prime_vmap, \
 	.gem_prime_vunmap	= drm_gem_cma_prime_vunmap, \
 	.gem_prime_mmap		= drm_gem_cma_prime_mmap, \
-	.dumb_create		= drm_gem_cma_dumb_create, \
-	.dumb_map_offset	= drm_gem_cma_dumb_map_offset, \
-	.dumb_destroy		= drm_gem_dumb_destroy
+	.dumb_create		= drm_gem_cma_dumb_create
 
 /**
  * TINYDRM_MODE - tinydrm display mode