drm/amd/display: Register init

[Why]
Driver re-initialize registers already set in FW

[How]
Transfer init to FW

Signed-off-by: Igor Kravchenko <Igor.Kravchenko@amd.com>
Reviewed-by: Tony Cheng <Tony.Cheng@amd.com>
Acked-by: Eryk Brol <eryk.brol@amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>