drm/amd/display: Support DAC in dce110_hwseq

drm/amd/display: Support DAC in dce110_hwseq

The dce110_hwseq is used by all DCE hardware,
so add the DAC support here.

When enabling/disabling a stream for a RGB signal,
this will call the VBIOS to enable/disable the DAC.
Additionally, when applying the controller context,
call SelectCRTC_Source from VBIOS in order to
direct the CRTC output to the DAC.

Signed-off-by: Timur Kristóf <timur.kristof@gmail.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>