drm/amd/display: enable dchub request limit for DCN 3.2.x

[why]
HW recommend we enable this for better DF QoS for DCN 3.2.x

[how]
Add interfaces to hubbub to program register
Add initialization as part of init_hw
Add default settings for DCN 3.2.x
Add registry override for debug/tuning

Reviewed-by: Alvin Lee <Alvin.Lee2@amd.com>
Acked-by: Tom Chung <chiahsuan.chung@amd.com>
Signed-off-by: Jun Lei <jun.lei@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>