drm/amd/display: Turn off DAC in DCE link encoder using VBIOS

drm/amd/display: Turn off DAC in DCE link encoder using VBIOS

[ Upstream commit e021ee995056ee7e58114edd92bcd4578d8b4bb5 ]

Apparently, the VBIOS DAC1EncoderControl function is much more
graceful about turning off the DAC. It writes various DAC
registers in a specific sequence. Use that instead of just
clearing the DAC_ENABLE register.

Do this in just the dce110_link_encoder_disable_output
function and remove it from the HWSS.

Fixes: 0fbe321a93ce ("drm/amd/display: Implement DCE analog link encoders (v2)")
Signed-off-by: Timur Kristóf <timur.kristof@gmail.com>
Tested-by: Mauro Rossi <issor.oruam@gmail.com>
Suggested-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Alex Hung <alex.hung@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>