drm/amd/display: Fix when disabling secure_display

[Why]
Fix problems when we disable secure_display.

[How]
- Reset secure display context after disabled
- A secure_display_context is dedicate to a crtc, so we set the crtc for
it when we create the context.

Reviewed-by: Wayne Lin <Wayne.Lin@amd.com>
Acked-by: Jasdeep Dhillon <jdhillon@amd.com>
Signed-off-by: Alan Liu <HaoPing.Liu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>