It is fine for displays without audio functionality to not implement
CEA v3 extension in their EDID. Do not return an error in that case,
instead return 0 as if there was a CEA v3 extension with no audio or
speaker block.

This fixes the second half of bug fdo#107825:
https://bugs.freedesktop.org/show_bug.cgi?id=107825Signed-off-by: Jean Delvare <jdelvare@suse.de>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <maxime.ripard@bootlin.com>
Cc: Sean Paul <sean@poorly.run>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191115170736.7d88593d@endymion