drm/todo: Tick off some tinydrm entries

- Better manual-upload support for atomic
  The new damage helper has the necessary pieces to make this work.

- tinydrm_gem_cma_prime_import_sg_table
  This is now moved to the CMA helper and can be set using the
  DRM_GEM_CMA_VMAP_DRIVER_OPS macro.

- tinydrm_fb_create
  This is now covered by drm_gem_fb_create_with_dirty()

Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190115043643.2364-6-noralf@tronnes.org