drm/amd/display: Add back support for DSC 4:2:2 Simple

[why]
The requirement has been clarified and only DSC 4:2:2 Native has to
be disabled.

Signed-off-by: Nikola Cornij <nikola.cornij@amd.com>
Reviewed-by: Wenjing Liu <Wenjing.Liu@amd.com>
Acked-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>