Single-link DVI max dotclock is 165MHz. Filter out modes with higher
dotclock when the monitor doesn't support HDMI.
Modes higher than 165 MHz were allowed in
commit 
7d148ef51a657fd04036c3ed7803da600dd0d451
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Mon Jul 22 18:02:39 2013 +0200
    drm/i915: fix hdmi portclock limits
Also don't attempt to use 12bpc mode with DVI monitors.
Cc: Adam Nielsen <a.nielsen@shikadi.net>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=75345
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=70331
Tested-by: Ralf Jung <post+kernel@ralfj.de>
Cc: stable@vger.kernel.org
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
 {
        struct drm_device *dev = intel_hdmi_to_dev(hdmi);
 
-       if (IS_G4X(dev))
+       if (!hdmi->has_hdmi_sink || IS_G4X(dev))
                return 165000;
        else if (IS_HASWELL(dev) || INTEL_INFO(dev)->gen >= 8)
                return 300000;
         * outputs. We also need to check that the higher clock still fits
         * within limits.
         */
-       if (pipe_config->pipe_bpp > 8*3 && clock_12bpc <= portclock_limit
-           && HAS_PCH_SPLIT(dev)) {
+       if (pipe_config->pipe_bpp > 8*3 && intel_hdmi->has_hdmi_sink &&
+           clock_12bpc <= portclock_limit && HAS_PCH_SPLIT(dev)) {
                DRM_DEBUG_KMS("picking bpc to 12 for HDMI output\n");
                desired_bpp = 12*3;