drm/sun4i: hdmi: Support HDMI controller on A10

The HDMI controller in the A10 SoC is the same as the one currently
supported in the A10s. It has slightly different setup parameters.
Since these parameters are not thoroughly understood, we add support
for this variant by copying these parameters verbatim.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171017121807.2994-4-wens@csie.org