To help to determine if digital display port needs to enable
audio output or not. This one adds a helper to get monitor's
audio capability via EDID CEA extension block.
Tested-by: NWu Fengguang <fengguang.wu@intel.com>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>
Reviewed-by: NAdam Jackson <ajax@redhat.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>