drm/amdgpu: skip SMU FW reloading in runpm BACO case

SMU is always alive, so it's fine to skip SMU FW reloading
when runpm resumed from BACO, this can avoid some race issues
when resuming SMU.

Suggested-by: Evan Quan <evan.quan@amd.com>
Signed-off-by: Guchun Chen <guchun.chen@amd.com>
Reviewed-by: Lijo Lazar <lijo.lazar@amd.com>
Reviewed-by: Evan Quan <evan.quan@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>