drm/i915: Treat HDMI as DVI when cloning

drm/i915: Treat HDMI as DVI when cloning

When doing HDMI+non-HDMI cloning the other sink can't get
the infoframes/etc. so stuff like limited range output is
not a good idea.

Similarly when doing HDMI+HDMI cloning on g4x (only platform
where we allow it) only one of the ports can receive infoframes
and so again using any fancy stuff is a bad idea. We also don't
track the inforames/audio state per-port so we'd end up with
some kind of random mismash state when multipled encoders try
to compute the same stuff. And the hardware will in fact
automagically disable audio/infoframe transmission if you try
to enable it for multiple HDMI ports at the same time.

Thus disable all HDMI specific features when cloning.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221107194604.15227-4-ville.syrjala@linux.intel.com
Reviewed-by: Jani Nikula <jani.nikula@intel.com>