drm/edid: Add 6 bpc quirk for BOE panel.

BOE panel (ID: 0x0771) that reports "DFP 1.x compliant TMDS".
But it's 6bpc panel only instead of 8 bpc.

Add panel ID to edid quirk list and set 6 bpc as default to
work around this issue.

Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Gustavo Padovan <gustavo@padovan.org>
Cc: Cooper Chiou <cooper.chiou@intel.com>
Signed-off-by: Lee, Shawn C <shawn.c.lee@intel.com>>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/1540792173-7288-1-git-send-email-shawn.c.lee@intel.com

drivers/gpu/drm/drm_edid.c

@@ -119,6 +119,9 @@ static const struct edid_quirk {
 	/* SDC panel of Lenovo B50-80 reports 8 bpc, but is a 6 bpc panel */
 	{ "SDC", 0x3652, EDID_QUIRK_FORCE_6BPC },
 
+	/* BOE model 0x0771 reports 8 bpc, but is a 6 bpc panel */
+	{ "BOE", 0x0771, EDID_QUIRK_FORCE_6BPC },
+
 	/* Belinea 10 15 55 */
 	{ "MAX", 1516, EDID_QUIRK_PREFER_LARGE_60 },
 	{ "MAX", 0x77e, EDID_QUIRK_PREFER_LARGE_60 },