Some TCONs on newer SoCs doesn't support channel 0, since they are meant
to be used only with TV or HDMI encoder.

Prepare support for them with adding has_channel_0 quirk.
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net>
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180214200906.31509-8-jernej.skrabec@siol.net