drm/radeon/audio: write audio/video latency info for DCE6/8

Needed by the hda driver to properly set up synchronization
on the audio side.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>

diff --cc drivers/gpu/drm/radeon/dce6_afmt.c
Simple merge

diff --cc drivers/gpu/drm/radeon/evergreen_hdmi.c
Simple merge

diff --cc drivers/gpu/drm/radeon/sid.h
Simple merge