For real HDMI sink, CPT HDMI port has to set 'HDMI' mode flag
in order to make HDMI audio work correctly.

This is required patch for drm/i915 to enable HDMI audio on CPT PCH,
ALSA patch is at http://mailman.alsa-project.org/pipermail/alsa-devel/2010-May/027601.htmlTested-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Eric Anholt <eric@anholt.net>