drm/amd/display: Only allow dig mapping to pwrseq in new asic

[Why]
The old asic only have 1 pwrseq hw.
We don't need to map the diginst to pwrseq inst in old asic.

[How]
1. Only mapping dig to pwrseq for new asic.
2. Move mapping function into dcn specific panel control component

Cc: Stable <stable@vger.kernel.org> # v6.6+
Cc: Mario Limonciello <mario.limonciello@amd.com>
Link: drm/amd#3122


Reviewed-by: Anthony Koo <anthony.koo@amd.com>
Acked-by: Rodrigo Siqueira <rodrigo.siqueira@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Lewis Huang <lewis.huang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>