Merge tag 'sunxi-drm-for-4.14' of https://git.kernel.org/pub/scm/linux/kernel/git/mripard/linux into drm-next

Allwinner DRM changes for 4.14

A few changes, but most notably improving the HDMI support merged in 4.13,
by reporting the DDC adapter as an i2c bus, and by adding CEC support
through the CEC framework.

* tag 'sunxi-drm-for-4.14' of https://git.kernel.org/pub/scm/linux/kernel/git/mripard/linux:
  sun4i_hdmi: add CEC support
  dt-bindings: display: sunxi: Improve endpoint ID scheme readability
  drm/sun4i: tcon: remove unused function
  drm/sun4i: Remove useless atomic_check
  drm/sun4i: Add if statement instead of depends on
  drm/sun4i: hdmi: Implement I2C adapter for A10s DDC bus
  drm/sun4i: constify drm_plane_helper_funcs