drm/amdgpu: add RLC_PG_DELAY_3 for yellow carp

RLC_PG_DELAY_3 is to make RLC in safe mode to
prevent any misalignment or conflict in middle of any power
feature entry/exit sequence when CGPG feature is enabled.

Signed-off-by: Aaron Liu <aaron.liu@amd.com>
Reviewed-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>