drm/amd/display: enable fgcg by default

[why]
sw has most of the fgcg enabled which is the same as HW default.
but driver disabled some due to enable flag not initialized.

comparing HW state, we still need to enable dpp and dio.

Reviewed-by: Muhammad Ahmed <ahmed.ahmed@amd.com>
Acked-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
Signed-off-by: Charlene Liu <charlene.liu@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>