drm/amd/display: Fix brightness adjustment on MiniLED

[Why]
Older Asics were changed to target new DCN while still needing older
support causing brightness adjustments to fail.

[How]
Reverted the DCN targets on required DCNs

Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Reviewed-by: Iswara Nagulendran <iswara.nagulendran@amd.com>
Signed-off-by: Harry VanZyllDeJong <hvanzyll@amd.com>
Signed-off-by: Rodrigo Siqueira <rodrigo.siqueira@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>