drm/amd/pm: Skip use smc fw data in SRIOV

smc fw is not needed in SRIOV, thus driver should not try to get smc
fw data.

Signed-off-by: Jingwen Chen <Jingwen.Chen2@amd.com>
Reviewed-by: Emily.Deng <Emily.Deng@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>