Repeat enable dpm under pass-through because there is no actually
hardware-fini and real power-off when guest vm shutdown or reboot.
Otherwise, under pass-through it will be failed to populate populate
and upload SCLK MCLK DPM levels due to zero of pcie_speed_table.count.
Signed-off-by: Yintian Tao <yttao@amd.com> Reviewed-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>