drm/sun4i: tv: Convert to atomic hooks

The sun4i TV driver still uses legacy enable and disable hook
implementation. Let's convert to the atomic variants.

Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20220728-rpi-analog-tv-properties-v2-35-459522d653a7@cerno.tech