ARM: dts: sun4i: Enable HDMI support on some A10 devices

Various A10-based development boards have standard HDMI connectors
wired to the dedicated HDMI pins on the SoC.

Enable the display pipeline and HDMI output on boards I have or have
access to schematics:

  - Cubieboard
  - Olimex A10-OLinuXino-LIME

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>