drm/amd/display: Program DSC before enabling link

[why]
Link or DIG BE can't be exposed to a higher stream bandwidth than they
can handle. When DSC is required to fit the stream into the link
bandwidth, DSC has to be programmed before the link is enabled to ensure
this. Without it, intermittent issues such as black screen after S3 or a
hot-plug can be seen with DSC timings like 4k144Hz or 8k60Hz.

[how]
Move DSC programming from before enabling stream to before enabling link

Signed-off-by: Nikola Cornij <nikola.cornij@amd.com>
Reviewed-by: Jun Lei <Jun.Lei@amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>