drm/amdgpu: run partition schedule if it is supported

Run partition schedule if it is supported during ctx init entity.

Signed-off-by: James Zhu <James.Zhu@amd.com>
Acked-by: Lijo Lazar <lijo.lazar@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>