UPSTREAM: drm/edid: Clear old dvi_dual/max_tmds_clock before parsing the new EDID

UPSTREAM: drm/edid: Clear old dvi_dual/max_tmds_clock before parsing the new EDID

Clear out old max_tmds_clock and dvi_dual information (possibly from a
previous EDID) before parsing the current EDID. Tne current EDID might
not even have these in its HDMI VSDB, which would mean that we'd leave
the old stale values in place.

Change-Id: Ia0acb9ca673f8bf9badfda1cf99899298bae464b
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Acked-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1475070703-6435-3-git-send-email-ville.syrjala@linux.intel.com
Signed-off-by: Zheng Yang <zhengyang@rock-chips.com>
(cherry picked from commit 75d7e542bd3669a7ce41b713be8d3fd71e0ed2fa)