drm/radeon: rework audio modeset to handle non-audio hdmi features

Need to setup the deep color and avi packets regardless of
audio setup.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

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