drm/amdgpu: Enable light SBR in XGMI+passthrough configuration

This is to fix the case where it only enable the light SMU
on normal device init. This feature actually need to be enabled after ASIC
been reset as well.

Signed-off-by: shaoyunl <shaoyun.liu@amd.com>
Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>