drm/edid: Add EDID_QUIRK_FORCE_8BPC quirk for Rotel RSX-1058

Rotel RSX-1058 is a receiver with 4 HDMI inputs and a HDMI output, all
1.1.

When a sink that supports deep color is connected to the output, the
receiver will send EDIDs that advertise this capability, even if it
isn't possible with HDMI versions earlier than 1.3.

Currently the kernel is assuming that deep color is possible and the
sink displays an error.

This quirk will make sure that deep color isn't used with this
particular receiver.

Fixes: 7a0baa62 ("Revert "drm/i915: Disable 12bpc hdmi for now"")
Signed-off-by: NTomeu Vizoso <tomeu.vizoso@collabora.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170220152545.13153-1-tomeu.vizoso@collabora.com
Cc: stable@vger.kernel.org
Cc: Matt Horan <matt@matthoran.com>
Tested-by: NMatt Horan <matt@matthoran.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=99869Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>

drivers/gpu/drm/drm_edid.c

@@ -148,6 +148,9 @@ static const struct edid_quirk {
 
 	/* Panel in Samsung NP700G7A-S01PL notebook reports 6bpc */
 	{ "SEC", 0xd033, EDID_QUIRK_FORCE_8BPC },
+
+	/* Rotel RSX-1058 forwards sink's EDID but only does HDMI 1.1*/
+	{ "ETR", 13896, EDID_QUIRK_FORCE_8BPC },
 };
 
 /*