drm/i915/bios: Nuke DEVICE_TYPE_DP_DUAL_MODE_BITS

drm/i915/bios: Nuke DEVICE_TYPE_DP_DUAL_MODE_BITS

Replace the DEVICE_TYPE_DP_DUAL_MODE_BITS stuff with just
a DP+HDMI check. The rest of the bits shouldn't really
matter anyway.

The slight change in behaviour here is that now we do look at
the DEVICE_TYPE_NOT_HDMI_OUTPUT bit (via
intel_bios_encoder_supports_hdmi()) when we previously ignored it.
The one platform we know that has problems with that bit is VLV.
But IIRC the problem was always that buggy VBTs basically never
set that bit. So that should be OK since all it would do is make
all DVI ports look like HDMI ports instead. Also can't imagine
there are many VLV machines with actual DVI ports in existence.

We still keep the rest of the dvo_port/aux_ch checks as we
can't trust that DP+HDMI device type equals DP++ due to
buggy VBTs.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211217155403.31477-6-ville.syrjala@linux.intel.com
Reviewed-by: Jani Nikula <jani.nikula@intel.com>