drm/amd/display: Enable type C hotplug

[Why and How]
We want to change where timing is done for alt mode.
Some of the commented out #ifs are needed for DCN20
so we enable them for that case.

Signed-off-by: Eric Yang <Eric.Yang2@amd.com>
Reviewed-by: Eric Yang <eric.yang2@amd.com>
Acked-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>