drm/amdgpu: Remove SMU powergate message call for SDMA

SDMA v4.4.2 doesn't need explicit power gating control through PMFW

Signed-off-by: Asad kamal <asad.kamal@amd.com>
Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Reviewed-by: Lijo Lazar <lijo.lazar@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>