drm/i915: Use a dmi quirk to skip a broken SDVO TV output.

drm/i915: Use a dmi quirk to skip a broken SDVO TV output.

commit 6070a4a928f8c92b9fae7d6717ebbb05f425d6b2 upstream.

This IBM system has a multi-function SDVO card that reports both VGA
and TV, but the system has no TV connector.  The TV connector always
reported as connected, which would lead to poor modesetting choices.

https://bugs.freedesktop.org/show_bug.cgi?id=25787

Signed-off-by: Zhao Yakui <yakui.zhao@intel.com>
Tested-by: Vance <liangghv@sg.ibm.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>