drm/sun4i: Add driver support for A80 display pipeline

This patch adds support for the compatible strings of the A80 display
pipeline.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180315114136.24747-6-wens@csie.org