drm/amd/display: Add driver support for enabling PSR on DMCUB

[Why]
We want to be able to enable PSR on DMCUB, and fallback to
DMCU when necessary.

[How]
Move psr_on_dmub flag from dc_debug_options to dc_config.

Signed-off-by: Wyatt Wood <wyatt.wood@amd.com>
Reviewed-by: Tony Cheng <Tony.Cheng@amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>